Egyptian helicopters have bombarded several villages in the northern Sinai Peninsula region, witnesses reported, after a rise in attacks against soldiers in the unstable and often violent region.

Residents told Al Jazeera that the assault was launched on the villages of al-Tuma al-Mukataa and al-Mahdiya. The army this week vowed to stamp out armed groups operating in the region.

No casualties were been reported in Friday night's shelling.

On Saturday, Egyptian security officials said a roadside bomb had struck an army vehicle, also on Friday, injuring seven soldiers.

Armed groups have been battling security forces in the Sinai Peninsula for a decade

The blast near the city of el-Arish, near the Gaza border, came a week after an attack in the same area killed 31 soldiers.

It was the deadliest attack targeting security forces since the army toppled former president, Mohamed Morsi, in July.

Authorities declared a state of emergency, imposed a curfew, and launched a plan to demolish homes and create a buffer zone in response.

The army forcibly evacuated hundreds of families living along the border with the Gaza Strip in order to create the buffer zone, designed to stop the smuggling of fighters and weapons through underground tunnels.

Armed groups have been battling security forces in Sinai for a decade, but the violence soared after Morsi was overthrown, spreading to other parts of the country.

The armed groups have said the attacks are in retaliation to a sweeping crackdown by security forces, in which hundreds of Morsi supporters have been killed and about 20,000 people have been arrested.

The government has blamed much of the violence on Morsi's Muslim Brotherhood group, which it blacklisted as a "terrorist group" last year.

The Brotherhood, which officially renounced violence decades ago, has condemned the attacks and denied any involvement.

Source: Al Jazeera and agencies