Seven people have been killed in Egypt's Sinai Peninsula in an exchange of fire that hit their home, security and medical officials said.

It was not immediately clear whether it was a missile fired by one of the Egyptian army helicopters that have repeatedly struck fighters, or an errant mortar round from fighters, security officials told the AFP news agency.

The casualities in the house south of the Rafah border town in Tuesday's blast included women and children, medical officials said.

According to the AFP, they have not yet been identified.

Officials who spoke to the AP news agency on condition of anonymity said the civilians were from a prominent Bedouin family in the village of Negah Shabana.

They said it happened while the area was heavily shelled by fighters and the Egyptian military.

The officials said a 65-year-old woman was injured by shrapnel during the exchange of fire and was rushed to hospital for treatment.

Crackdown

The army has launched a massive crackdown against armed groups in Sinai area that has killed scores of policemen and soldiers, since the ouster of president Mohamed Morsi last year.

It has demolished hundreds of homes along the border with the Gaza strip, stoking tensions with area residents.

Egypt announced the demolition plan last month after fighters killed 31 Egyptian troops in an assault on a checkpoint 30km from Rafah.

Earlier this month a prominent Sinai-based group, Ansar Beit al-Maqdis, which claimed responsibility for that attack, announced its allegiance to the ISIL, or the Islamic State of Iraq and the Levant, and its leader Abu Bakr al-Baghdadi.

Civilians in the mostly Bedouin towns of Sinai had been caught in the crossfire before, with several killed by an errant mortar round.

Source: Agencies