Yemeni security forces have detained a local al Qaeda leader suspected of links to an attack that killed a top military commander earlier this week, a security source said.

Yemeni security forces have tightened security across the country after a suicide bomber killed Major General Salem Qatan, the commander of military forces in southern Yemen, on Monday after his forces drove al Qaeda allies Ansar al-Sharia from their strongholds in the Abyan province.

A Yemeni security source said Sami Dayyan, who they believe is a local al Qaeda leader, was captured along with two other suspected militants while travelling by car to Lahej province from the port city of Aden, Reuters reports.

The source said that explosives and suicide belts were found in the vehicle, which was stopped for a routine search outside Aden on Thursday evening. The three men were being questioned.

"They were in the process of preparing for operations similar to the one that killed Qatan," the source said.

He said that the three had "entered Aden in previous days to prepare for the operation in which Qatan was assassinated".

Al Qaeda said in a statement on Thursday that one of its members had killed Qatan for his role in the U.S.-backed offensive that drove Ansar al-Sharia out of cities they had captured during last year's uprising that eventually forced President Ali Abdullah Saleh to step down.

Qatan's death highlighted the tenuous grip of Yemen's central authorities on the south despite weeks of a U.S.-supported campaign to crush the militants.

Residents of the al-Mansoura district of Aden said they had spotted Dayyan looking to rent a house in the neighbourhood a few days ago and chased him away.