Egypt’s President Mohamed Mursi has visited the spot near the Israeli border where gunmen killed 16 police officers on Sunday.
The visit came as Cairo deployed helicopter gunships to the Sinai Peninsula to hunt the militants.
It is thought they were Islamic extremists. However, Mursi’s Muslim Brotherhood’s website said the Iraeli intelligence service, Mossad, could have been behind it.
Israeli Prime Minister, Benjamin Netanyahu, who also visited the scene, dismissed the claim but said the strike was a wake-up call for Cairo.
The Sinai region is largely demilitarised. But growing lawlessness over the last year has opened the door to Bedouin bandits, extremists and Palestinian militants.
The 35 gunmen are said to have entered Egypt from Gaza and then crossed into Israel where israeli police killed eight of them.
Egypt has now closed the Rafah crossing into the Gaza Strip and pledged to regain control of the area – a promise that might appease locals around Rafah who have been burning tyres and chanting anti-Mursi slogans, accusing the government of not doing enough to protect them.