Egyptian aircraft struck at targets near the border with Israel today and troops raided villages as a crackdown began on Islamic militants blamed for a deadly attack on Egyptian border police, army officials and witnesses said.
Israel, urging Egypt to deal with a growing threat on its southern flank, voiced approval of the security sweep, the biggest military assault in the area since their 1973 war.
The air strikes around the town of Sheikh Zuwaid, 10km from the Palestinian-ruled Gaza Strip, followed clashes overnight between armed men and security forces at several checkpoints in the north of Egypt's Sinai region.
Gunmen killed 16 border guards on Sunday in the bloodiest attack on security forces in Sinai since Egypt made peace with Israel in 1979. The attackers stormed through the border into Israel but they were killed by Israeli fire.
The militants, sworn to destroy Israel, have stepped up their actions on the isolated desert frontier since an uprising toppled Egypt's autocratic leader Hosni Mubarak last year.
The new president, Mohamed Mursi, a more moderate Islamist who took office in June, tried to allay Israeli concerns with promises to bring the region back under government control.
But Mr Mursi has also brought Egypt closer to the Islamist Hamas movement ruling Gaza, making this a delicate time in relations between the Jewish state and the Arab power.
The militant strongholds are in northern Sinai. Red Sea resorts further south are popular with foreign tourists and a lifeline for Egypt's struggling economy.
The Egyptian army, which kept peace with Israel throughout the Mubarak years and still has broad sway over national security, promised retribution after Sunday's attacks and brought in 500 extra soldiers and police.
But there was no crackdown until last night after armed men opened fire on several checkpoints in al-Arish town, the security and administrative centre for northern Sinai.
Gunmen also attacked checkpoints in Rafah, Egypt's entry point into the Gaza Strip that borders both Israel and Egypt.
Earlier this morning, witnesses in Sheikh Zuwaid said two military planes flew over the area and heard explosions. Other people near the town said they saw three cars bombed.
Egypt's military leadership said ground and air forces had begun to restore stability in Sinai.
"The forces were able to execute the plan successfully. The forces will continue the plan and calls on tribes and families of Sinai to cooperate in the restoration of security," it said.
Troops entered al-Toumah village, 20km to the south, acting on information that militants were staying there, army commanders in Sinai said. One said 20 militants were killed.
A villager said he saw military helicopters chasing vehicles out of al-Toumah and heard rocket fire. The men in the cars fired back with machine guns, he said. An army general in al-Toumah said helicopters destroyed three vans in which militants tried to escape.
The military response focused on Shaikh Zuwaid, a mud-brick settlement that relies heavily on profits from smuggling goods and people through tunnels into Gaza since the Palestinian territory was cut off from Israel.
Egypt said the gunmen behind Sunday's attack arrived via the tunnels and it began work to seal them off yesterday.
Reuters