Hundreds of Yemeni troops backed by tanks advanced in a bid to retake a coastal town from Al Qaeda-linked fighters yesterday, residents said, part of a US-backed offensive in a country Washington sees as a frontline against Islamist militants.

“They are getting ready to fight,” one resident, who declined to be named, said by telephone. Via text message, the head of the southern military zone asked people living in the area not to use the roads around Shaqra and two other towns controlled by militants.

Shaqra lies on Yemen’s southern coast, along a major shipping route that is also the gateway for Somalis entering the country to fight alongside militants.

The US and its Gulf allies are alarmed by deteriorating security in Yemen, where Al Qaeda-linked militants gained a foothold during a popular uprising against former president Ali Abdullah Saleh.

While Saleh grappled with the protests that eventually toppled him, militants went on a rampage in the southern province of Abyan, gunning down officials, looting ammunition depots, and for the first time in history, seizing territory.

The US, which helped engineer Saleh’s replacement by his deputy in February, is backing the offensive in the south and has stepped up its campaign of drone strike assassinations of alleged Al Qaeda members who it says plot attacks from Yemen.

Yemeni troops have moved into the centre of Zinjibar, capital of Abyan province, where they fought militants on Sunday. They also clashed with Islamist fighters near the town of Jaar, some 30km to the north.

Meanwhile, two suicide bombers targeting an army checkpoint in Loder, another town in Abyan, killed four people and wounded another, said the defence ministry. The bombers, one of whom was dressed as a woman, were also killed.

“The attack was targeting Colonel Mohamed Batreeh, the head of military intelligence in Abyan province,” a local official said. “He survived, but the innocent people were the ones who got killed.”

A third suicide bomber struck in the same place later on, blowing himself up when volunteer pro-government fighters told him to surrender.

Militants retreated last month from Loder after encountering stiff resistance from fighters who have arranged themselves into popular committees to defend their land.

“Getting rid of those (Islamist fighters) needs time. They are like a plague,” said Abu Saada, a tribesman fighting alongside the army in Abyan.

While fighting raged in the south, at least 34 people were killed in clashes overnight between Sunni Muslim Salafis and Houthi Shia rebels in northern Yemen.

A spokesman for the Salafis said Houthi fighters attacked them on Sunday night in the Kataf area of the northern Saada province.

“We have regained control of a mountain site in the Al Damaj area after heavy clashes with the Houthis during which 18 of the attackers were killed along with 16 of ours,” the spokesman said yesterday. Dozens were wounded in the clashes, he said.