SANAA - Three al Qaeda militants were captured in Yemen early on Saturday, close to the Saudi Arabian border, a Yemeni security official said.

Meanwhile, Shi'ite rebels, in conflict with government forces in northern Yemen and cross-border fighting with Saudi Arabia, said they had shot down a Saudi military helicopter.

The Apache helicopter was hit as it was joining Saudi forces in the mountainous Jabal Dukhan border area, which has been the site of heavy fighting since rebels carried out a raid there in November, the rebels' website said.

Saudi Defence Ministry spokesman General Ibrahim al-Malek could not be reached immediately for comment.

The Yemeni security official told Reuters that the detained militants had weapons, explosives and leaflets with them.

On Friday, six al Qaeda militants were killed in an air strike in northern Yemen in a stepped-up government campaign against the Islamist group.

Separately, German magazine Der Spiegel reported on Saturday that kidnappers holding five Germans hostage in Yemen want to swap them for prisoners who the Yemeni government believes have al Qaeda links, as well as $2 million (1.2 million pounds) in ransom.

Yemen came under the spotlight after crackdowns on al Qaeda in Pakistan and Afghanistan raised concern it was becoming a training and recruiting centre for militants.

Yemen stepped up its operations against al Qaeda after a Yemen-based wing of the group said it was behind an attempt to blow up a Detroit-bound U.S. airliner on December 25.

Saudi Arabia said last week its forces had killed hundreds of Yemeni rebels in a slice of Saudi territory. Four Saudi troops had been killed, it said.
The rebels, called Houthis after their leaders' clan, say they crossed the border in November only because Saudi Arabia was letting Yemeni forces use its territory to attack them.

Yemeni authorities said last week their forces had killed 19 rebels in house-to-house fighting in the northern city of Saada in a continuing operation dubbed Blow to the Head.

(Reporting by Mohamed Sudam; Writing by Tamara Walid and Firouz Sedarat; Editing by Louise Ireland)