The sources said the attack was in retaliation for an army raid on the home of a tribal chief, Sheikh Nasser Gammad bin Dawham, who stood accused of sheltering al-Qaeda members. They gave no details on the raid.
On June 5, a Yemeni colonel and two soldiers were killed in an attack by suspected al-Qaeda members near the city of Maarib as they travelled in convoy to inspect military forces stationed in the Safar oilfield.
Yemeni forces have been battling al-Qaeda operatives in Maarib for four days. The government say it aims to catch suspected al-Qaeda fighters believed to be behind the ambush.
Tribesmen from Maarib, where al-Qaeda has a strong presence, last month set ablaze two oil pipelines near the Safer fields but the authorities have since repaired the damage.
Yemen is the ancestral homeland of al-Qaeda leader Osama bin Laden.
The group has suffered setbacks amid US pressure on Sanaa to crack down.