Egypt launched airstrikes on militants suspected of involvement in an attack on a mosque in the restive northern Sinai that killed 235 people, the army said on Saturday.
The overnight strikes near the site of the massacre killed an unspecified number of suspects and destroyed some vehicles used in Friday's attack, army spokesman Colonel Tamer al-Refai said in a statement on Facebook.
"The strikes also targeted a number of terrorist hideouts that housed weapons and ammunition," he added.
"Law enforcement forces, in cooperation with air forces, are combing other terrorist spots."
Egyptian President Abdel-Fattah al-Sissi, a former army general, vowed a "harsh" response to the attack, which prosecutors said also left 109 injured.
The attack on the mosque began shortly after noon prayers, when the assailants detonated explosive devices around al-Rawdah mosque in the village of the same name, located in the town of Bir al-Abd about 40 kilometers west of the northern Sinai city of al-Arish.
Masked gunmen then opened fire on the worshippers fleeing from the blasts.
The mosque is linked to Sufi Muslims, who are regarded as heretics by extremist terrorist groups as Daesh.
Many of those killed were buried in mass graves in al-Rawdah village late Friday, local witnesses said.
The burial rituals were conducted amid heavy security including the closure of main roads in the area for fear of further militant attacks, the witnesses added.
Private newspaper al-Masry al-Youm reported that more than 20 gunmen were involved in the mosque attack and that they used automatic rifles.
Egypt has declared three days of national mourning.
No group has yet claimed responsibility for the attack. Militants affiliated with the Daesh terrorist group have claimed previous attacks in Egypt.
The earlier attacks mainly targeted security forces and the country's minority Christian community. Assaults on mosques are rare.
Egypt has seen a spate of deadly militant attacks since 2013 when the army toppled democratically elected President Mohamed Morsi.
