Gunmen have shot dead at least nine health workers who were administering polio vaccinations in the northern Nigerian city of Kano, police say.
The attacks in two different locations happened on Friday morning.
Witnesses said the attackers arrived on three-wheel taxis and opened fire, also killing the vaccine workers' driver.
Officials with Nigeria's police and military did not immediately respond to requests for comment.
Kano, Nigeria's second largest city, has been regularly targeted by Boko Haram, an armed group which has condemned the use of Western medicine.
Nigeria remains one of the few countries left in the world where polio remains endemic.
Several years ago religious clerics had some of their followers stop receiving the vaccines saying that it would sterilise their children.
Via: Al Jazeera English
Bad news i must say.
Hope we experience nothing like it again
The north doesn't even sound like the best place to be in right about now.
This is terrible