A total of 20 Al-Qaeda suspects were killed in two air strikes in northeast and southern Yemen, the defence ministry and witnesses said on Sunday.

The witnesses said three of the men were killed when a missile set ablaze and destroyed their car on a desert road in the Samda region between the provinces of Jouf and Marib.

A number of other people in the vehicle were wounded.

The defence ministry said earlier that 17 suspected Al-Qaeda militants were killed in an air raid that struck one of their hideouts in the southern town of Loder late on Saturday.

The strike brought to 57 the number of Islamist insurgents reportedly killed in south Yemen over a three-day period, according to the defence ministry. AFP could not independently verify the toll.

"Seventeen Al-Qaeda terrorists were killed in an air raid that targeted one of their positions southeast of Loder," the defence ministry's news website 26sep.net reported.

It was unclear if the strikes were carried out by the Yemeni air force or by US drones. On Wednesday, the Washington Post said US drones have carried out eight air strikes in Yemen in the past four months.

Islamist militants have been trying to seize control of Loder in the restive southern province of Abyan to expand their grip on the region.

According to the Washington Post, the Central Intelligence Agency is seeking permission to launch more airborne drone strikes in Yemen, even when there is a risk the victims might not always be terrorists.

If President Barack Obama's administration gives the CIA permission for the strikes, it could represent a politically dangerous escalation of US military activity in Yemen, the Post said.

The United States has never formally acknowledged the use of drones against Al-Qaeda in Yemen, considered by Washington to be the most active and deadly branch of the global terror network.

Al-Qaeda has exploited a decline in Yemeni central government control that accompanied Arab Spring-inspired protests since last year and eventually forced veteran president Ali Abdullah Saleh to resign.

The army, backed by armed civilians, has been battling the extremist group's Yemeni branch, known as the Partisans of Sharia, for control of Abyan province, most of which has fallen under the rule of the Islamist insurgents.

The militants strengthened their control over Abyan after they overran its capital Zinjibar last May, prompting deadly battles with the army.