CAIRO, Egypt -- An al Qaeda-inspired group based in Egypt's Sinai has claimed responsibility for the suicide bombing of the police headquarters in a Nile Delta city that killed 16 people the day before.

Ansar Beit al-Maqdis, or the Champions of Jerusalem, says it carried out a suicide bombing in the northern city of Mansoura to avenge the "shedding of innocent Muslim blood" at the hands of Egypt's "apostate regime" -- a reference to the security forces' crackdown on Islamists following the July military coup that ousted Islamist President Mohammed Morsi.

The claim was posted Wednesday on a militant website the group has used before. It identified the suicide bomber in Tuesday's attack by his nickname, Abu Mariam.

The group has claimed responsibility for several attacks before this.