SANAA (Reuters) - A gunman shot dead a Yemeni security officer near the interior ministry in the centre of the capital Sanaa on Wednesday, a police source said, blaming al Qaeda.

Several security personnel have been killed in recent months in the unstable Arabian Peninsula country where militant groups stepped up activities during a revolt against the president.

The gunman drove away on a motorbike driven by a second man, the source said, declining to be identified.

"The assassination resembles the many operations that have targeted intelligence and security officers in recent months," the source said.

"It is clear that it bears the fingerprints of al Qaeda but until now we don't have proof," the source added.

Attacks on security officials and politicians increased after Yemen's army, backed by U.S. drone strikes, pushed Islamist militants out of towns in the southern Abyan province.

Yemen's uprising ousted president Ali Abdullah Saleh in February. Saleh's successor Abd-Rabbu Mansour Hadi has promised to crush the militants.

Washington and Yemen's neighbor Saudi Arabia are keen to stop al Qaeda and other Islamist militants strengthening their hold on a country which is close to major shipping lanes.

(Reporting By Mohammed Ghobari, writing by Raissa Kasolowsky; Editing by Andrew Heavens)