Sana’a: At least four people were killed during clashes between Al Qaida-linked militants and pro-government tribesmen in Marib province, east of the Yemeni capital Sana’a, a tribal source said early on Wednesday.

Three of the dead were Islamist militants and the fourth was a tribesman fighting on behalf of the government, the source said.

The tribesmen, on whom the government depends heavily in its fight against Islamist militancy, have been seeking those responsible for the killings of 17 army officers and soldiers in an ambush on Saturday.

The soldiers were killed inspecting a pipeline in the Wadi Obaida area of oil-producing Marib province. The pipeline had been the target of attacks by Islamist militants and tribesmen.

Yemeni military planes also struck at Al Qaida insurgents suspected of being behind the ambush on Tuesday.

“Under an agreement between tribal chiefs and the authorities, the military will cease the air strikes and the tribesmen will chase those responsible for [Saturday’s] attack,” one tribesman said.

Yemen’s stability is a priority for the United States and its Gulf Arab allies because of the impoverished Arab state’s strategic position next to top oil exporter Saudi Arabia and shipping lanes, and because it is home to one of the most active wings of Al Qaida.

The tribesman said the three militants had been hiding in a local farm used by Al Qaida-linked militants.

The Yemeni-based Al Qaida in the Arabian Peninsula has mounted operations in Saudi Arabia and attempted attacks against the United States, which has stepped up strikes by drones.

The US-backed military offensive has driven the militants out of areas they seized in the south last year but has not prevented them from launching attacks that have dealt damaging blows to the army and security apparatus.

In June, the commander of military forces in the south of Yemen was killed by a suicide bomber in the port city of Aden.