Egyptian authorities freed Monday a Briton who was arrested in the restive north Sinai town of El-Arish for possessing clothes similar to police uniforms, state media reported.

The Briton, who was not identified, was released on the orders of the general prosecution of El-Arish, said the official MENA news agency.

Witnesses said Egyptian military helicopters launched a second day of air raids on Sunday in Sinai in what the army described as "the largest military operation" to uproot Islamist militants.

Apache helicopters hit targets in north Sinai near the Rafah border crossing with the Islamist Hamas-ruled Gaza Strip, witnesses said.

Egyptian air strikes in the Sinai Peninsula killed at least eight militants and destroyed a weapons depot, the military and local residents said on Sunday.

The overnight strikes against "a terrorist group" responsible for killing police and army troops in north Sinai left "25 people dead and injured", army spokesman Colonel Ahmed Aly said.

Egypt's military on Wednesday said it had killed 60 "terrorists" in Sinai in the month after Mohammed Morsi's ouster on July 3, which fueled militant attacks in the restive peninsula.

The military "killed 60 individuals", according to a bullet-point video it released, titled "Losses of terrorist elements in exchanges of fire with security forces".

Gunmen killed two Egyptian soldiers and a policeman on Sunday in three separate attacks in the restive Sinai peninsula, which borders Israel, security and medical sources told Agence France Presse.

The unidentified assailants in the town of El-Arish shot dead one soldier in front of the television and broadcasting building and another who was on guard duty, and killed the policeman in an attack on a police station, a security source said.

Gunmen clashed with the Egyptian army on Sunday near the Israeli border, security sources said, in the latest violence to erupt in the Sinai peninsula since the ouster of president Mohammed Morsi.

The fighting broke out in the area of al-Wifaq, in northern Sinai, after militants tried unsuccessfully to blow up a police vehicle with explosives.

Armed Bedouin tribesmen freed a Hungarian peacekeeper in Egypt's Sinai after briefly detaining him on Thursday to press for the release of a jailed relative, police officials said.

The Bedouin set the soldier free after tribal leaders intervened, and the kidnappers had not realized they were capturing a member of the Multinational Force and Observers (MFO) stationed in the peninsula, the police said.

An Egyptian police officer and six recruits were wounded on Friday when gunmen attacked their patrol in the Sinai Peninsula, security officials said.

The patrol had been tasked with protecting the cross-Sinai pipeline that supplies Egyptian gas to Israel and Jordan and which has been the target of 15 separate attacks since 2011.

Egypt is searching for 120 wanted militants and believes around 1,600 extremists are hiding out in the Sinai, where militants have attacked soldiers and police, the official news agency MENA reported on Wednesday.

The military sent in tanks and soldiers into the lawless peninsula which neighbors Israel and Gaza after gunmen killed 16 soldiers in an attack on an army outpost on August 5.

Egypt's army vowed Monday to "avenge" the killing of 16 troops by gunmen near the Israeli border, as President Mohammed Morsi ordered security forces to take full control of the Sinai Peninsula.

In Sunday's attack, 35 gunmen in Bedouin clothing opened fire on the troops before crossing into the Jewish state in an armored vehicle, Egyptian officials said. Israel said five gunmen were killed on its side.