An international human rights group says satellite images show widespread destruction in two Nigerian towns that were recently attacked by Islamic extremists.

Amnesty International said Wednesday that the detailed images of Baga and Doron Baga, taken before and after the attack earlier this month, show that more than 3,700 structures were damaged or completely destroyed.

Amnesty says the images were taken Jan. 2 and Jan. 7. Boko Haram fighters seized a military base in Baga on Jan. 3 and, according to witnesses, killed numerous civilians in the ensuing days.

The Nigerian military cites a figure of 150 dead, including slain militants. Amnesty International says interviews with witnesses and others suggest hundreds of civilians were shot; last week, the human rights group noted reports of as many as 2,000 dead.