Two militants drove a car packed with explosives into a Yemeni army base in the south of the country on Saturday, killing themselves and a soldier, the Defence Ministry said.

The attack targeted barracks of the Republican Guard forces in the province of al-Bayda at dawn, the ministry said on its website. It blamed al Qaeda for the blast.

The explosion was very loud and took place in Dar al-Nasr, which is a military site of the Republican Guard, said a website close to Ali Mohsen al-Ahmar, a general who defected from former President Ali Abdullah Saleh in the early days of an uprising against him last year.

Residents of the town were frightened by the force of the blast, which was felt more than two kilometres away and damaged dozens of neighbouring houses and blew their windows out.

Militants linked to al Qaeda have exploited a year of political upheaval in Yemen to strengthen their foothold there, particularly in the south, which is also home to rising secessionist sentiment.

Gunmen opened fire on a U.S. security team as it trained Yemeni soldiers in the south of the country on Friday, the Pentagon and a security official said.

The United States and Saudi Arabia, wary of al Qaeda entrenchment in Yemen, backed a Gulf-brokered plan under which Saleh handed power to his deputy Abd-Rabbu Mansour Hadi, who was sworn in last month.

The Republican Guard, which is commanded by Saleh's son Ahmed Ali, was also the target of a suicide bombing that killed at least 26 people on the day of Hadi's swearing in.

(Reporting by Mohammed Ghobari; Writing by Isabel Coles; Editing by Alessandra Rizzo)