A Yemeni court specialising in terrorism cases began the trial on Sunday of six Al-Qaeda suspects accused of murdering a Saudi diplomat and kidnapping a Swiss woman.

The defendants, two of them being tried in absentia, are charged with forming part -- between 2011 and 2013 -- of "an armed group linked to Al-Qaeda," the official Saba news agency reported.

The group are accused of murdering a Saudi diplomat in November 2012.

Sergeant Khaled Shobeikan al-Anzi, an official at the Saudi embassy's military section in Yemen, was killed along with his bodyguard in Sanaa when gunmen opened fire at his car.

They are also charged with carrying out the kidnapping of language teacher Sylvia Eberhardt from Switzerland in March 2012, who spent nearly a year in captivity before her release, according to Saba.

The next hearing was set for 23 February.

Yemen is the ancestral home of Al-Qaeda founder Osama bin Laden and home base of Al-Qaeda in the Arabian Peninsula, the network's deadliest franchise according to the United States.

AQAP was formed in January 2009 as a merger of the Yemeni and Saudi branches of Al-Qaeda.

Its militants took advantage of a decline in central government control during a 2011 uprising that forced veteran president Ali Abdullah Saleh from power to seize large swathes of territory across the south.

They were driven back in June 2012 and have been increasingly weakened mainly due to US drone attacks. But they still carry out hit-and-run attacks against security forces.