German airline Lufthansa and its subsidiary Austrian Airlines have suspended flights to Libya indefinitely due to security concerns in the North African country.

A Lufthansa spokesman announced the decision on Monday, saying Lufthansa, Austrian, Italy's Alitalia and British Airways "decided to suspend flights to Tripoli indefinitely due to security and operational reasons," Reuters reported.

The decision came two weeks after a bomb exploded on the main runway at Tripoli airport, highlighting the deteriorating security situation in the country.

Libya has been witnessing numerous clashes between government forces and rival militia groups, who played a key role in the 2011 popular uprising that toppled former dictator Muammar Gaddafi.

The former rebels refuse to lay down arms despite efforts by the central government to impose law and order.

On Sunday, public and private sector staff, including oil workers, went on strike in the port city of Benghazi, protesting against worsening security.

The strikers also demanded the resignation of the parliament whose mandate has expired. Many Libyans blame infighting parliamentarians for the growing turmoil and anarchy in the country.

The strikers said government forces failed to improve security in Libya, more than three years after the onset of the revolution that ousted Gaddafi.