[Update 10:59 a.m. ET] U.S. Secretary of State Hillary Clinton said there were no reports of U.S. casualties in Tuesday's Taliban attacks in Kabul. The country "will take all necessary steps" to secure the area and keep personnel safe, Clinton said.

She said the "dedicated, brave men and women" from the United States who work for the Afghan people "will not be intimidated" by this cowardly act.

See a list of attacks on other U.S. diplomatic sites over the years.

[Update 10:56 a.m. ET] The Afghan Public Health ministry said one civilian was killed and at least 18 were wounded but none seriously in Tuesday's Taliban attacks in Kabul.

[Update 10:09 a.m. ET] Three police officers have been killed in a string of attacks by the Taliban in Kabul on Tuesday, police in the capital said.

[Update 9:37 a.m. ET] In a Twitter message, ISAF said a "suicide attacker was identified & killed by ANP before reaching target near Kabul airport," making reference to the Afghan National Police. There were no further details.

[Update 9:04 a.m. ET] The Afghan Interior Ministry said four suicide attackers entered the building site from which the attack on the U.S. Embassy and ISAF headquarters is being carried out. Two of them were killed and two were "resisting."

[Update 8:56 a.m. ET] What does today's Kabul violence say about U.S. chances for success in Afghanistan? TIME reports.

[Update 8:48  a.m. ET] An ISAF official said there are initial reports that some insurgent rounds hit the NATO base and caused minor damage.

[Update 8:29  a.m. ET] The U.S. Embassy issued an emergency message about the series of attacks across Kabul on Tuesday, saying "the situation is uncertain and ongoing.  There are media reports that many roads are closed in Kabul." It said appointments for visas or U.S. citizen services have been canceled for now and it said Americans in Afghanistan should monitor the websites of the embassy and the State Department's Bureau of Consular Affairs for the latest information.

"We urge U.S. citizens to shelter in place, avoid unnecessary movement, and to avoid the neighborhood around the U.S. Embassy: Wazir Akbar Khan, Microrayon, and Massoud Circle," it said.

"The Embassy also urges U.S. citizens to remain vigilant and avoid areas where Westerners congregate.  Do not discuss travel plans or other personal matters with strangers, or in public.  Be alert and aware of your surroundings, and always travel with mobile phones or appropriate communication equipment."

[Update 8:27  a.m. ET] A coalition officer and a senior ISAF official both confirmed to CNN that there had been intelligence that insurgents might launch a high-profile attack in the capital around the 10th anniversary of the September 11, 2001, attacks.

[Update 8:23  a.m. ET] An Afghan MI-35 helicopter gunship is attacking a building from which insurgents are firing, The Telegraph reports in a blog post.

[Update 7:59 a.m. ET] A senior ISAF official says less than 10 insurgents are involved in attack on the U.S. Embassy and nearby ISAF headquarters. There are no casualties among ISAF personnel, the official says.

[Update 7:51 a.m. ET] Iran's English-language Press TV says its offices in Kabul have come under attack. Several people are injured, it says.

[Update 7:44 a.m. ET] NATO Secretary-General Anders Fogh Rasmussen said the Taliban attacks in Kabul on Tuesday were an attempt to derail plans to hand over security responsibility to Afghan forces in Afghanistan.

"We are witnessing that the Taliban try to test (the) transition but they can't stop it. Transition is on track and it will continue," Rasmussen said.

[Update 7:40 a.m. ET] Sidiq Sidiqi, an Afghan Interior Ministry spokesman, said a police officer has been killed and security forces have killed "two of the suicide attackers in the building" near the U.S. Embassy. He said police think there are two or three more attackers in the structure.

[Update 7:31 a.m. ET] Black Hawk helicopters are firing on insurgents in a Kabul building, the Guardian reports in a blog post.

[Update 7:24 a.m. ET] Afghan security forces killed two attackers firing on coalition targets from a building in central Kabul Tuesday, an Interior Ministry spokesman said.

[Update 7:23 a.m. ET] The Taliban said its fighters also struck a police convoy in the western part of Kabul. No further details are available.

[Update 7:18 a.m. ET] U.S. Embassy says no casualties among embassy personnel from Taliban attack in area of the embassy.

[Update 7:12 a.m. ET] Taliban militants staged a major assault against high-profile coalition targets in central Kabul Tuesday, a brazen strike by the tenacious Islamist movement in Afghanistan's capital.

"Our insurgents attacked in Kabul city," Taliban spokesman Zabiullah Mujahid told CNN. "Their target is the U.S. Embassy, governmental organizations and other foreign organizations."

Militants opened fire near the U.S. Embassy and NATO's International Security Assistance Force headquarters Tuesday after they stormed into a nearby abandoned building, U.S., NATO and Afghan officials said.

The location of the building is next to Abdul Haq Square, a few blocks from the U.S. Embassy, an intelligence officer told CNN. An embassy spokeswoman said staff there have been told to take cover.

The Afghan National Directorate of Security said the firefight with insurgents was ongoing.  Militants were using rocket-propelled grenades and light weapons. A hospital official said two injured civilians were being treated and expect to handle more casualties.

Central Kabul is considered high-security area, and it is protected by police and other security forces.

The area has been cordoned off, according to Gen. Mohammed Zahir, the head of criminal investigation for the police.

This is the latest major attack by the Taliban in a violent period that coincides with the anniversary of the September 11, 2001 attack on the United States.

Over the weekend, two Afghan laborers were killed, and 77 U.S. troops and 25 Afghan workers were wounded in a Taliban truck bombing on an ISAF base in Afghanistan's Wardak province.

Last month, Taliban suicide bombers killed at least eight people in Kabul when they attacked the British Council. That's a British-government-affiliated body that fosters cultural and academic exchanges.

[Update 6:40 a.m. ET] Five suicide attackers are involved in the attack in central Kabul, Reuters news agency quotes a senior Kabul police official as saying.

[Update 6:35 a.m. ET] Militants opened fire near the U.S. Embassy and NATO's International Security Assistance Force headquarters in central Kabul Tuesday after they stormed into a nearby abandoned building, U.S., NATO and Afghan officials said.

The Afghan National Directorate of Security said the firefight with insurgents was on-going.  Militants have fired rocket-propelled grenades and light weapons.

Central Kabul is a high-security area, protected by police and other security forces.

The area has been cordoned off, according to Gen. Mohammed Zahir, the head of criminal investigation for the police.

The Taliban claimed responsibility, a spokesman said.

"Our insurgents attacked in Kabul city," Taliban spokesman Zabiullah Mujahid said.  "Their target is the U.S. Embassy, governmental organizations and other foreign organizations."

There have been a number of recent attacks in Kabul that the Taliban has claimed responsibility for.

[Update 6:17 a.m. ET] The headquarters of the NATO-led International Security Assistance Force (ISAF) is also under Taliban attack, news reports from Afghanistan say.  The attack appears to involve a number of suicide bombers in Kabul, the BBC reports.

[Update 6:00 a.m. ET] Staff at the U.S. Embassy in Kabul took cover Tuesday as militants fired on the city center from a building they took over a few blocks away, U.S. and Afghan officials said.

The Afghan National Directorate of Security said rocket-propelled grenades have been fired at the embassy.

The area has been cordoned off by police as they battle the insurgents, according to Gen. Mohammed Zahir, the head of criminal investigation for the police.

The Taliban claimed responsibility, a spokesman said.

"Our insurgents attacked in Kabul city," Taliban spokesman Zabiullah Mujahid said.  "Their target is the U.S. Embassy, governmental organisations and other foreign organisations."

[Update 5:50 a.m. ET] Gunmen fired on U.S. Embassy from nearby abandoned building, CNN's Suzanne Malveaux reports from Kabul. Embassy personnel told to take cover, Malveaux reports.

[Update 5:43 a.m.] Militants fired on the U.S. Embassy in central Kabul Tuesday after taking over a building a few blocks away, security officials said.

The Taliban claimed responsibility for the attack, a spokesman said.