Gunmen believed to be linked to al Qaeda killed four soldiers and an officer at a checkpoint on Friday in southeastern Yemen, a local official said.

Two other soldiers were wounded in the attack on the checkpoint outside al-Qatan, one of the largest cities in Hadramout province, the official told Reuters.

Also on Saturday an aide to a senior Yemeni government military adviser and three security guards were wounded when a bomb exploded near his car, security sources said.

It was not immediately clear who planted the device on a road in the capital Sanaa, then detonated it as Fawaz al-Dhibri's vehicle went past, the sources added. All four were in a stable condition in hospital.

Yemen has been plunged into turmoil since pro-democracy protests in 2011 forced president Ali Abdullah Saleh to step down after 33 years in office. Authorities have since struggled to rein in rival political factions and tribes, southern separatists and Islamist insurgents.

Dhibri is the director of the office of General Ali Mohsen al-Ahmar, who broke away from the army during the anti-Saleh protests and said he was siding with the demonstrators.

His First Armoured Brigade occasionally clashed with forces loyal to Saleh during the uprising.

The general was taken on as a military adviser by Saleh's replacement, President Abd-Rabbu Mansour Hadi, in 2013.

On Friday, the Yemeni Interior Ministry said on its website that "terrorist elements" attacked a checkpoint operated by soldiers, causing deaths and injuries, but gave no specific figures.

"Forces from the 37th Armoured Brigade are pursuing the perpetrators of this cowardly terrorist attack," the ministry said in a statement.

Six soldiers, 10 suspected militants and a 10-year-old boy died earlier this week in a coordinated attack by a suicide bomber and militant fighters on the headquarters of the army's Fourth Division in Aden, which controls southern Yemen.-TradeArabia News Service