Five people have been killed by two drone strikes in Yemen's southern province of Abyan, the country's interior ministry says.

A ministry statement released on Friday said that the men were al-Qaeda suspects, and that they were killed on Thursday.

The statement did not whether the drones were launched by Yemen or the United States.

However, local officials in Abyan, which was a stronghold for Yemen-based al-Qaeda in the Arabian Peninsula (AQAP) and other armed groups during an uprising that ousted veteran President Ali Abdullah Saleh last year, told the Reuters news agency that the drones were American.

AQAP is regarded by the United States as one of the most active wings of the network, posing a serious threat to Western interests including oil tanker traffic in the Gulf.

Last year, the Yemeni army, with US backing, drove al-Qaeda fighters and their allies from some of their southern strongholds.

The fighters have since regrouped and mounted attacks on government officials and installations.

The US regularly launches drone strikes against AQAP in a campaign that has been criticised by rights groups as executing suspects without trial, with civilians often killed alongside terrorism suspects.

Sectarian clashes continue

Meanwhile, fighting between Shia Muslim rebels and hardline Sunni Muslims continued to rage in the country's north on Friday.

Security officials said on Friday that the sectarian clashes killed two people in recent fighting, the latest deaths in ongoing clashes that have left dozens dead over the past 10 days.

Shia Houthi rebels have been fighting ultraconservative Salafis and jihadists in the city of Damaj in the northern Saada province.

Security officials said on Friday that 12 people also were injured in the last two days.

The officials spoke on condition of anonymity because they were not authorised to brief the media.

Serour al-Wadie, a spokesman of the Salafi movement, said Houthis used mortars and rocket-propelled grenades in an attack Friday on a mosque in Damaj.

Earlier this week, Yemeni President Abd Rabbo Mansour Hadi warned of sectarian strife and urged both sides to stop the violence in remarks aired on state television.