At least 11 people have been killed and several others wounded in a gun attack near a military camp at the Kenyan border with Somalia.

It is believed the victims were workers from a local quarry in Mandera county in the north-east of the country.

Residents told the BBC they had heard two explosions, followed by heavy gunfire in the middle of a night.

Militia group al-Shabab, which operates out of Somalia, has been linked to the attack.

Mandera County Commissioner Alex Ole Nkoyo told AFP people were sleeping when the gunmen struck.

"These were al-Shabab from the nature of the attack. They used explosives and guns," he added.

Kenya Red Cross said it was sending an aircraft to the scene to fly the injured to hospitals in Nairobi.

Constant threat

Al-Shabab has not confirmed its involvement, but its militants have been behind a series of similar attacks in the region.

Their deadliest assault to date happened at a university in the Kenyan town of Garissa in April, when four gunmen killed 148 people.

In 2013, at least 67 people died in a gun attack on the Westgate mall in the capital Nairobi.

People from other parts of Kenya working in the north-east have threatened to leave the area following frequent al-Shabab attacks.

The Islamist group has carried out numerous attacks near the long porous border with Somalia.

This latest incident is likely to put the spotlight on the Kenyan authorities again over their handling of the security situation.

Just two weeks ago the government lifted a night-time curfew in the area after Muslim clerics said it impeded prayers during the month of Ramadan.