A Tunisian diplomat has been kidnapped in the Libyan capital Tripoli, Libya's foreign ministry said, two days after gunmen seized Jordan's ambassador.

A spokesman for the foreign ministry said it was unclear who was behind the kidnapping of the Tunisian diplomat on Thursday.

An official in Tunisia's foreign ministry confirmed the abduction.

"We cannot confirm that he has been kidnapped but we have been unable to contact him," he told Reuters news agency.

The kidnapped diplomat is the second staffer from the Tunisian embassy abducted in the Libyan capital since March 21 when a man employed by the mission was seized. His fate is still unknown.

On Tuesday masked gunmen kidnapped Jordan's ambassador, Fawaz Aitan, as he rode to work in Tripoli, shooting at his car and wounding his driver. 

Security has deteriorated in Libya as the government has been unable to control armed groups who helped topple Muammar Gaddafi in 2011 but refuse to disarm.

Diplomatic staff and missions have borne the brunt of the unrest.

In January, gunmen seized five Egyptian diplomats and held them for several hours.

Two assailants were killed in October when protesters attacked Russia's embassy in Tripoli, and a car bomb attack on the French embassy wounded two guards a year ago.

On September 11, 2012, an attack on the US consulate in the eastern city of Benghazi, the cradle of the 2011 revolt, killed US Ambassador Chris Stevens and three other American citizens.

Source: Agencies