Egyptian military officials say the number of suspected militants killed by airstrikes in the Sinai Peninsula has risen to 13.
The officials say Apache helicopters fired missiles at houses used as hideouts and gathering points for the suspected militants.
The explosions resounded for miles and smoke rose in the sky from the targeted villages. Officials spoke on condition of anonymity because they were not authorized to speak to the press.
A long-running military offensive has been stepped up after militants shot down a helicopter earlier this week, killing all its crew members.
The al-Qaida-inspired Ansar Beit al-Maqdis, or Champions of Jerusalem, claimed responsibility.
Ansar attacks have surged since the military toppled Islamist President Mohammed Morsi in a July coup.