Editor's note: CNN correspondent Arwa Damon has reached the besieged Syrian city of Homs, which opposition forces say has been under a sustained artillery bombing for days.
Damon is one of a few reporters in Syria, where the government has been placing restrictions on international journalists and refusing many of them entry at all. Below is an edited account of what Damon and her team are seeing and hearing from activists in Homs as attacks continue:
The thick black smoke rising across the skyline is from an oil pipeline that is believed to have been hit. We heard three explosions at around 6:30 in the morning. Shortly thereafter a thick plume of black smoke began covering the skyline here. This is not the first time we have seen these type of images emerging from the besieged city of Homs. That pipeline has been hit on at least two other occasions.
At around 7:30 a.m. local time the sustained bombardment began. We heard various sounds of artillery being fired as well as sporadic, heavy automatic machine-gun fire. This has been the status quo in Homs for more than a week now.
The Syrian military has really intensified its offensive here, especially in the neighborhood of Baba Amr. Activists say they believe the Syrian government is on a campaign to flatten every single neighborhood where there has been some sort of opposition, some sort of effort to try to stand up to this government.
Just to give you an idea of how intense the bombardment has been, Tuesday morning activists said they counted around 55 explosions in just the span of 15 minutes. They say that has been the norm. You can only imagine the type of pressure that they have been under, especially when it comes to trying to deal with the number of dead and the number wounded. In many parts of the city, they have been unable to get medical supplies in.
And in these makeshift clinics that they have set up, they aren't able to treat the wounded adequately because of a lack of medical supplies and because they only have the most basic medical equipment at their disposal. There has been an intensified effort on the part of the activists here to try to find various routes out of the besieged neighborhoods to get medical supplies in and to get the wounded out. Many of the wounded require much greater treatment than what people are able to provide at these clinics.
About 1 million people live in the city of Homs. We've been hearing people have been fleeing from some areas to other parts of the city. They've effectively been living with four, five, six families to a house in areas they are not able to get out of.
A lot of these areas that the Syrian government is hitting are in fact the poor parts of the city. Baba Amr, for example, is one of the most impoverished neighborhoods inside the city of Homs.
Families are gathering in makeshift shelters that are effectively the basements of some houses. Most houses here actually don't have basements, but the few that do have become makeshift shelters, where dozens of families are gathering along with their children. These are families that are either unable to get out or don't have the means to. They are effectively being forced to try to stay put.
Even when they do try to flee activists are telling us they often come under attack. There's a great problem we've heard reported that snipers are on basically every building, making any sort of escape routes an extreme real challenge. Activists say that people just trying to cross the street, women and children, are being sniped out.
You can just imagine the situation people are under, not just from a dangerous standpoint, but the psychological impact that this is having on these families, these civilians, who are stuck in these areas unable to get to safe ground or unable to get adequate medical treatment should they be hit in these attacks.
When it comes to those who have died, even trying to bury them has become an equally dangerous task.
In many instances they have to bury those they've lost under the cover of darkness or in makeshift graves. There have been a few cases where they've tried to bury the bodies of the dead under the cover of darkness - and even in those instances people say they've come under fire.
What's even more disturbing is that the activists say since this most recent campaign began in Homs 10 days ago, they believe hundreds have been killed. They don't have an accurate count on the death toll though, and that is because they still believe countless numbers of bodies are buried under the rubble.
There are a number of buildings that have come crumbling down because of the bombardment, where activists believe there were families inside - sometimes it is their families or relatives whom they haven't heard from in days. Quite simply, they can't reach these areas.
Movement in many parts of the city during the day is just about impossible. It's virtually a suicide run to try to move around for so many people. They have to move with extreme caution, so it's hard to gauge the magnitude, the human death toll, of this most recent escalation in violence.
Again, this has been the status quo in Homs for more than 10 days now, and that is just a result of the most recent military crackdown, not to mention that for months now many parts of the city have been under siege.
That is why so many of the activists here are so desperate, trying to reach out to the international community. They are unable to comprehend how in the 21st century that this type of onslaught can be taking place in full view of the international community of global powers, of various humanitarian agencies, and yet no concrete action has been really taken to bring a true end to the violence here.
Read more dispatches from the attacks in Syria: