BENGHAZI, Libya — A suicide bomb attack at an army base outside Benghazi in eastern Libya killed at least six people and wounded up to 15 on Sunday, medical and security sources said.

The attacker blew himself up in a car in front of the base in Barsis, some 30 miles outside Benghazi, a security source said.

All those killed were soldiers, medical sources said, but the security source said the attacker was among those killed.

The security situation has sharply deteriorated in Libya's second-largest city in the past few months where car bombs and assassinations of army and police officers happen regularly.

Most countries closed their consulates in Benghazi after a series of attacks and some foreign airlines have stopped flying there. The U.S. ambassador and three other Americans were killed in September 2012 during an Islamist assault on the consulate.

Western diplomats worry the violence in Benghazi will spill over to the capital Tripoli which last month saw the worst fighting in months between militias.

Much of Libya's oil wealth is located in the east where many demand autonomy from the Tripoli government, adding to turmoil in the North African country.

(Reporting by Ayman al-Warfalli; Writing by Ulf Laessing; Editing by Sandra Maler)