Daesh group jihadists launched an unprecedented wave of attacks Wednesday on soldiers in Egypt's Sinai Peninsula, killing at least 70 people, in a major challenge to President Abdel Fattah al-Sisi.

F-16 warplanes bombarded the militants as they fought security forces on the streets of the North Sinai town of Sheikh Zuweid after striking military checkpoints in a surprise attack after dawn.

The militants withdrew from the town after almost eight hours of fighting, the officials said.

The military in a statement said 17 soldiers and 100 militants were killed, but in the past it has given lower tolls for such attacks that it increases days later.

The violence came two days after state prosecutor Hisham Barakat was assassinated in a Cairo car bombing. He was the most senior government official killed in the jihadist insurgency.

In the capital on Wednesday, police killed senior Muslim Brotherhood member Nasser al-Houfi and eight others during a raid on an apartment, security officials and a member of the Islamist movement said.

The Sinai attacks, in which car bombs were used, were the most brazen in their scope since jihadists launched an insurgency in 2013 following the army's overthrow of Islamist president Mohamed Morsi.

The 70 dead were mostly soldiers but included several civilians, according to security and medical officials, who added 38 militants were also killed.

"It's unprecedented, in the number of terrorists involved and the type of weapons they are using," said a senior military official.

- Gunmen on the streets -

Militants took over rooftops and fired rocket-propelled grenades at a police station in Sheikh Zuweid after mining its exits to block reinforcements, a police colonel said.

F-16 jets struck the militants in several locations, officials and a witness said.

"There are gunmen on the streets. They have planted mines everywhere," said the witness.

Explosions were heard and plumes of smoke seen over Sheikh Zuweid from the neighbouring Gaza Strip, witnesses there said.

Daesh group said its jihadists surrounded the police station after launching attacks on 15 checkpoints and security installations using suicide car bombers and rockets.

Troops regularly come under attack in the Sinai, where jihadists have killed hundreds of policemen and soldiers since Morsi's overthrow.

In a statement released online, Daesh said the assault had involved three suicide bombers.

"In a blessed raid enabled by God, the lions of the caliphate have simultaneously attacked more than 15 checkpoints belonging to the apostate army," the group said.

Sisi pledged to toughen laws and suggested fast-track executions following the state prosecutor's assassination, and a cabinet meeting on Wednesday passed the amendments.

Sisi, the former army chief who toppled Morsi before winning elections last year pledging to wipe out militants, is expected to ratify the decisions quickly.

The government designated Morsi's Muslim Brotherhood a "terrorist group" in December 2013 as part of a crackdown on the opposition that has left hundreds of his supporters dead and thousands in jail.

Courts have sentenced hundreds to death, including Morsi, who was convicted of involvement in attacks on police stations.

His sentence is being appealed.

- Months of bloodshed -

The government often blames the Brotherhood for attacks, but the deadliest have been claimed by the IS affiliate in Sinai.

Wednesday's attack was similar to a series of ambushes on April 2 in which dozens of militants attacked checkpoints, killing 15 soldiers.

The militants kidnapped a soldier and later killed him.

In January, a rocket and car bomb attack on a military base, police headquarters and residential complex for troops and police killed at least 24 people, most of them soldiers.

The attacks have come despite stringent security measures in the Sinai, including a night-time curfew and the creation of a buffer zone along the Gaza border.

The dominant jihadist group in the Sinai, previously known as Ansar Beit al-Maqdis, or Partisans of Jerusalem, pledged allegiance to IS in Iraq and Syria last November.

It is believed to be led by a shadowy Egyptian cleric, Abu Osama al-Masry, and has recruited at least one former special forces officer.

The militants have mostly focused their attacks on soldiers and police, killing hundreds since Morsi's overthrow.

They previously said they avoided targeting civilians but claimed responsibility for a suicide bombing on a tourist coach in February 2014 that killed three South Koreans and their driver.

Police foiled an attempted attack at a pharaonic temple crowded with tourists in Luxor last month.
Source: AFP