Nine polio vaccinators were killed Friday morning in the northern Nigerian city of Kano, a police spokesman told CNN.
The victims, eight women and one man, were working for a government program established to vaccinate people across Nigeria. The killings are under investigation; police said they have no suspects.
According to the World Health Organization, Nigeria is one of only three countries in the world that have never stopped transmission of polio, along with Pakistan and Afghanistan.
[Updated at 1:29 p.m. ET] Islamist rebels would have taken Mali's capital had France's military not intervened in the African nation in the last few days, French President Francois Hollande said Tuesday.
"If we had not taken up our responsibility and if on Friday morning we had not acted with this intervention, where would Mali be today?" he asked.
The French defense minister told CNN that up to 800 troops are in Mali to help Malian forces in an offensive against Islamist militants, and that up to 1,700 total French forces - including the 800 in Mali - are involved in a variety of capacities, such as offering logistical support from various French military bases across Africa.
Hollande, speaking on a visit to the United Arab Emirates, said France intends to "make way as quickly as possible" for an African force.
Read more about France's military intervention, which began Friday.
[Updated 10:23 a.m.] The eight deaths in the attack at St. Rita Catholic church include the suicide bomber, an emergency official told CNN.
The wounded had critical injuries and were taken to four hospitals in Kaduna, said Musa Ilallah, regional coordinator for the National Emergency Management Agency said.
As NEMA responded, angry Christian youth began "beating our staff and as a result broke the side glass of our ambulance that was on the scene to provide service," said Ilallah, who spoke to CNN from the scene of the attack.
[Updated 9:10 a.m.] At least eight people were killed and 100 were injured in the attack, a spokesman for the National Emergency Management Agency said. One man was also burned alive in a reprisal attack.
Scores of people have been killed in church bombings in the country in recent years.
The Boko Haram militant Islamist group has previously claimed responsibility for church bombings that killed dozens.
[Posted 5:58 a.m.] A suicide bomber drove an explosive filled car into a church in Kaduna, Nigeria, according to the National Emergency Management Agency. First responders are on the scene, but the number of casualties is not known yet.FULL STORY