Ansar Beit al-Maqdis, in a statement posted on a militant website, said that a drone that crossed into Egyptian airspace killed four fighters as they were preparing a cross-border rocket strike into Israel. It said the dead were from Egyptian Sinai tribes.

Egyptian security officials, speaking anonymously Friday, said that a drone firing from the Israeli side of the border had killed five suspected militants.

The conflicting accounts could not be reconciled. Both said the site of the strike was about five kilometre inside Egypt.