AL-ARISH — Egyptian aircraft Wednesday struck at targets near the border with Israel and troops raided villages in a crackdown on militants blamed for a deadly attack on Egyptian border police, army officials and witnesses said. The air strikes around the town of Sheikh Zuwaid, 10 km from Palestinian-ruled Gaza Strip, followed clashes between armed men and security forces at several checkpoints in the north of Egypt's Sinai region. The crisis has emerged as a major test for President Mohamed Morsi, the country's first Islamist head of state. The beleaguered president Wednesday fired Murad Muwafi, his intelligence chief, and the governor of Northern Sinai. In a major shake-up, Morsi also asked Defense Minister Hussein Tantawi to replace the commander of the military police, a force that has been heavily used since the ouster 18 months ago of Hosni Mubarak. Morsi also fired the commander of the presidential guards and named new chiefs for security in Cairo and the police's large central security, a large paramilitary force often deployed to deal with riots. On Tuesday, Morsi stayed away from the military funeral for the 16 slain soldiers — a conspicuous absence for a leader whose thorny relationship with the military is being closely watched. Angry Egyptians heckled Prime Minister Hesham Qandil when he arrived for prayers before the funeral, prompting his security detail to whisk him out. Wednesday's airstrikes killed at least 20 suspected militants, state television reported. There was no independent corroboration of the claim, but witnesses confirmed hearing warplanes and loud blasts in the area. The strikes occurred amid reports of a new wave of attacks by suspected militants on checkpoints along the main road that connects Cairo and the Gaza Strip. State television reported that the military was hunting down militants in El Risa, El Khorouba, and the Beir Abd mountains, all sparsely populated areas. The reported air strikes marked a sharp escalation of violence in an increasingly lawless area that has the potential to become a powder keg. The presence of security forces along the desert peninsula has thinned out during the past two years, as militants and Bedouin tribes have stockpiled heavy weapons. Some activists have vowed to beat back any heavy-handed attempt by security forces to assert control of the Sinai. The Egyptian army still keeps broad sway over national security. But Morsi has also brought Egypt closer to the Islamist Hamas movement ruling Gaza, making this a delicate time in ties between the Jewish state and the Arab power. — Agencies