Militants fired a barrage of rockets and set off a car bomb Thursday killing at least 25 people, mostly soldiers, in Egypt's North Sinai province, where security forces are battling a raging Islamist insurgency.
Jihadists have regularly attacked security forces in the Sinai Peninsula since Islamist president Mohamed Morsi was ousted by then army chief and now President Abdel Fattah al-Sisi in July 2013.
They say this is in retaliation for a government crackdown against Morsi supporters that has left hundreds dead, thousands jailed and dozens sentenced to death after speedy trials the United Nations says is "unprecedented in recent history".
The main focus of Thursday's attacks was El-Arish, the provincial capital, where a military base, a nearby police headquarters and a residential complex for army and police officers were targeted in the biggest such incident since October.
Twenty-four people, mostly soldiers, were killed in a nearly simultaneous assault of rockets and the car bomb.
Security officials said militants first fired rockets at the El-Arish police headquarters and the military base, which was followed by the car bomb.
Minutes later a barrage of rockets struck the nearby housing complex.
The attack was the deadliest since an October 24 assault, also near El-Arish, when militants killed 30 soldiers and wounded scores more.
Separately, an army officer was killed in a rocket attack on an army checkpoint in the town of Rafah, on the border with the Gaza Strip.
Overall, officials said at least 34 people, including nine civilians, were wounded.
The October 24 attack prompted the authorities to build a buffer zone along the Gaza border to prevent militants infiltrating from the Palestinian enclave.
The buffer was initially planned to be 500 metres (546 yard) wide, but is now being doubled in width.
The authorities have also imposed a state of emergency in parts of North Sinai since the October attack.
They have poured troops and armour into the peninsula to fight the insurgency that surged after Morsi's ouster.
In August 2013, just weeks after that event, 25 soldiers were killed in the peninsula when gunmen opened fire at two buses transporting troops.
Jihadist group Ansar Beit al-Maqdis (Partisans of Jerusalem) has claimed most of the attacks.
In November the group pledged its allegiance to the Islamic State group, which has captured large chunks of territory in Iraq and Syria.
Ansar Beit al-Maqdis has also claimed several beheadings of men it accused of being informants for the Egyptian and Israeli forces.