https://www.cnet.com/news/sri-lanka-easter-bombings-social-media-access-restored/

The militant group ISIS claimed responsibility for bombings of Christian churches and hotels in three cities. The death toll, which was tallied at 321 by April 23, was lowered to 253 by the health ministry on Thursday, according to CNN. 

"Some of the bodies get severely damaged in these kinds of explosions and it's possible for some bodies to get completely destroyed or break into parts, making the identification of full bodies difficult," the ministry told CNN in a statement. "Hence, counting an exact death toll is challenging."