A US drone strike targeting armed militants mistakenly hit a house in Yemen's southeastern province of al-Bayda late on Wednesday, killing two children, witnesses said, while police sources said another drone strike on the east of the capital Sanaa killed seven more people.

Residents in Radda town in al-Bayda province said the pilotless warplane struck the house of Abdu Mohammed al-Jarrah, killing two of his children and injuring three others of the family.

A provincial police official told Xinhua by phone that the airstrike was targeting four al-Qaida operatives driving two motorbikes near the village of Kaifah but mistakenly hit a civilian house.

It was the fourth time that US drones have mistakenly hit civilian targets in Yemen after air raids killed 13 civilians in Radda in September last year and 40 women and children in the southern province of Abyan in 2010.

Such strikes sparked mass anger across the country against the Yemeni and US governments. Tribal relatives of the victims usually block roads linking major cities or cut off oil supplies to protest the air raids.

Meanwhile, another drone strike hit a vehicle on a road about 30 km east of the capital Sanaa, killing at least seven al-Qaida operatives including two Saudi nationals, the Yemeni Interior Ministry said in a statement which was obtained by Xinhua.

The drone fired four missiles on the pick-up vehicle laden with explosives in Sanhan area, about 10 minute drive from Yemen's largest arms market in Jihana district, the ministry said.

The fresh air raids brought the death toll of al-Qaida suspects to 22 after five successive US drone strikes on several targets in the Yemeni provinces of Marib and al-Jawf over the past four days.

Dozens of al-Qaida members have been killed in such airstrikes since Yemeni President Abd-Rabbu Mansour Hadi was sworn in in February 2012, after a yearlong unrest weakened the control of the central government and allowed the militants to take over swaths of territory in the south.

The Yemeni government managed to recapture several of those southern cities in May 2012.