ADEN - At least 20 militants and seven soldiers were killed in Yemen on Wednesday when government troops fought off an ambush by Islamist militants on the edge of a southern town controlled by an al Qaeda-linked group fake ray ban sunglasses, an army official said.

Islamist fighters attacked a position recaptured earlier this week by Yemeni forces to the west of Jaar, a town which the army is closing in on as part of a U.S.-backed drive to stabilize the country.

Several towns in the region, including Jaar, were overrun by militants during a popular uprising last year that severely weakened central government control over swathes of Yemen and eventually toppled former President Ali Abdullah Saleh.

The United States and its Gulf Arab allies are increasingly alarmed by deteriorating security in Yemen, home to al Qaeda's Arabian Peninsula wing (AQAP), which is seen by Washington as a serious threat internationally.

Backed by the United States, the Yemeni army has launched a major aerial and ground offensive in the south of the country, where militants have gone on the rampage in recent months, looting ammunition depots and killing scores of soldiers.

The defense ministry said in a text message that an air strike on Wednesday targeted a gathering of militants in the coastal town of Shaqra, which AQAP-linked fighters also control.

Further north, the army clashed with militants in the town of Radda, about 170 km (105 miles) south east of the capital Sanaa. AQAP-linked fighters briefly seized Radda earlier this year but left after striking a deal with the authorities.

The United States has thrown its weight behind Yemen's new President Abd-Rabbu Mansour Hadi fake ray bans, whom U.S. officials say is proving a more effective partner than Saleh in the war against Islamist militants.

Washington has increased drone attacks against militants it suspects may be plotting against it. It has also renewed military training to help Yemeni security forces rout al Qaeda.

But militants have carried out some of their most deadly attacks yet since Hadi took office vowing to crush them.