Gunmen shot dead a Yemeni army colonel and his son on Sunday when he stopped his car at a roundabout in his hometown, a local official said, extending a string of assassinations of top armed forces figures by suspected Islamist militants.

Four passersby were also wounded when the gunmen, who were on foot, fired on Colonel Ahmed al-Marfadi, deputy commander of the 37th Armored Division, and his son when they stopped at a traffic light in the center of the town of al-Qatan in the province of Hadramout, the government official said.

There was no immediate claim of responsibility for the attack. Yemeni officials have blamed similar assassinations on Islamist militants linked to al Qaeda. Several Yemeni news websites published pictures of Marfadi's body lying inside his four-wheel drive vehicle after the attack.

Tackling lawlessness in Yemen, situated near important oil shipment routes and bordering the world's biggest oil exporter Saudi Arabia, is an international concern for the US and other Western countries. Yemen is the base of an al Qaeda branch that has planned international bomb attacks.

Marfadi was the latest victim in a campaign targeting senior officers from the army and various security services that began in 2012. Yemenis say more than 80 officers have been killed, many by gunmen on motorcycles.

In the most recent shooting before Sunday's attack, Colonel Abdulrahman Mohammed al-Shami was gunned down in October while leaving his home in the capital Sanaa.

As well as battling an Islamist insurgency in south Yemen, the Sanaa government faces a southern separatist movement and a revolt among some tribes in the impoverished north of the Arabian Peninsula country.-Reuters