Egypt’s military says it is continuing an operation against armed groups in the Sinai believed to have been plotting attacks on security forces and other targets.

Security sources told Al Jazeera on Sunday that at least seven people were killed overnight, and six arrested in a raid.

The raid follows an airstrike by the Egyptian military on Friday, which saw at least four people killed.

The assault on Saturday happened when Apache helicopters hit areas south of Sheikh Zuwaid in north Sinai, according to Egyptian state media. 

A witness told Al Jazeera that armed fighters responded by firing towards the helicopters.

The armed group, Ansar Beit al-Maqdis, had earlier said Israeli drones were behind the attack a day earlier that killed four of their fighters. It accused the Egyptian army of co-ordinating the attack with the Israelis.

Israel's defense minister, Moshe Yaalon, says that his country will not let 'rumors and speculation' harm the Israeli-Egyptian peace treaty.

A funeral was held for the fighters on Saturday, with the bodies of the four driven through several border towns in Sinai.

Dozens of men on pick-up trucks flying their black flag paraded through the towns, in an act of defiance to the army, witnesses said.

"Our heroes became martyrs during their jihadi duties against the Jews in a rocket attack on occupied lands," Ansar Bayt al-Maqdis said on its website.

Fresh assault

Hours later, Egyptian military helicopters targeted fighters in an assault near the village of Touma in north Sinai, according to witnesses.

Colonel Ahmed Ali, the military spokesman, said in a written statement that the military "surveilled and dealt with a group of terrorists" involved in past attacks in the peninsula.

Meanwhile, unidentified men fired at police station in the coastal town of Al Arish without casualties on either side. 

Fighters based mainly in the northern Sinai near Israel's border have escalated attacks on security forces and other targets since July 3, when the army ousted President Mohamed Morsi and installed a new government in Cairo.

But the army has been reluctant to confront the fighters inside towns in order not to provoke the tight-knit tribes, military sources said.

Egypt and Israel have co-operated in tackling armed groups in Sinai in the past.

The Egyptian army said on Wednesday it had killed 60 fighters in the Sinai Peninsula in the month since July 3.

Source: Al Jazeera and agencies