The Palestinian Authority has condemned the network of smuggling tunnels between Hamas-run Gaza and Egypt as a "threat" to security and lauded Cairo's campaign to seal them.

Speaking a week after a deadly attack which killed 16 Egyptian border police in northern Sinai, Tayeb Abdelrahim, chief of staff to Palestinian President Mahmoud Abbas, expressed full support for Egyptian moves.

Egyptian security forces killed six gunmen in a raid on a village in North Sinai early Sunday, witnesses said, as the military pressed a campaign against Islamist militants in the lawless peninsula.

State television reported three soldiers were killed in the exchange of fire, but security officials told AFP they had died in a road accident elsewhere in Sinai some five hours before the raid.

The United States and Egypt are trying to put together a new security assistance package to address the worsening situation on the Sinai Peninsula, The New York Times reported late Saturday.

The Egyptian military has been bolstering its presence in the Sinai with tanks and helicopters after Sunday's unprecedented ambush on a border guard outpost near the borders of Gaza and Israel, which left 16 Egyptian soldiers dead.

Egypt has asked Gaza's Hamas rulers for information on three members of an Islamist group suspected of involvement in a deadly attack on a military outpost, a senior security official said on Saturday.

He said Egyptian authorities had received a list of nine suspects from Israel, and asked the Palestinian Islamist movement Hamas to provide information on three of the men.

The Egyptian army has arrested six "terrorists" during a sweep in the Sinai Peninsula following a raid at the weekend that killed 16 soldiers, military and security sources said on Friday.

Three independent Egyptian newspapers ran white boxes on Thursday in the space where their editorials are usually found in protest at what they say is a bid by the Muslim Brotherhood to control the media.

"The space is white to protest against attempts by the Brotherhood to impose its control over the press and media belonging to the Egyptian people," wrote al-Watan which, along with al-Masry al-Youm and al-Tahrir, did not publish editorials.

Egyptian President Mohammed Morsi ordered spy chief Murad Muwafi on Wednesday to retire in a shuffle of military and intelligence ranks after the deadliest militant attack on troops in decades.

The decision extended to Abdel Wahab Mabrouk, the governor of North Sinai where a weekend attack that killed 16 soldiers took place.

Egyptian helicopter gunships killed 20 militants in in the Sinai on Wednesday, state media and the army said, days after 16 soldiers were killed in an attack attributed to Islamist extremists.

The air strikes on Tumah village -- the military's first in Sinai for decades -- were carried out as security forces massed near Rafah on the Gaza border for what they called a decisive confrontation with the militants.

Egypt's defense minister led mourners in a military funeral on Tuesday for 16 soldiers killed by Islamist militants near the border with Israel in the deadliest such attack in decades.

The minister, Field Marshal Hussein Tantawi, was joined by senior government officials and generals in a brief procession that followed the caskets, wrapped in the military flag, after prayers.

Israel has returned to Egypt the bodies of "between six and eight" gunmen involved in a deadly attack in northern Sinai who then forced their way over the Israeli border, a military spokesman said on Tuesday.

Speaking to AFP, he said that some of the bodies had been so badly torn apart by explosives that it was impossible to be sure how many there were.