Explosions rocked five polling stations in eastern Libya yesterday as voters elected a body to draft a new constitution, another step in the Opec producer’s rocky transition since Muammar Gaddafi fell in 2011.

Nobody was wounded in the dawn bomb attacks in the restive town of Derna, residents said, but the incident highlighted the volatile situation in the North African country.

Prime Minister Ali Zeidan’s government is struggling to assert its authority over militias which helped topple Gaddafi but kept their weapons and have become major political players.

Two of the most powerful militias threatened on Tuesday to dissolve the General National Congress (GNC) assembly, Libya’s interim Parliament, which they accuse of paralysing the country by endless infighting.

There is no constitution but Islamic law

Libya desperately needs a viable government and system of rule so that it can focus on reconstruction and on healing the divisions exposed by the Nato-backed campaign against Gaddafi.

Polling stations opened across most of Libya, although they stayed closed in Derna after suspected Islamists forced one voting centre to shut by firing shots into the air and shouting “voting is haram (forbidden)”, an election official said.

Security conditions meant some polling stations in two other towns also failed to open.

In Benghazi, gunmen threw a bag full of explosives into a polling station but the devices did not go off, a security source said.

Nobody claimed responsibility for the Derna attacks but residents said the bombers had scrawled “There is no constitution but Islamic law” on a wall near the scene of one blast, suggesting radical Islamists were responsible.

Early voting appeared sluggish in the capital, Tripoli, and the main eastern city of Benghazi, where soldiers guarded polling stations. Helicopters circled over Tripoli.