Interior Minister Fawzi Abdelali resigned on Sunday after coming under fire for the performance of security forces during a surge of violence that has rocked Libya, an official from his office told AFP.
"He submitted his resignation to protest against congressmen criticising the government and to defend the revolutionaries," the official said, referring to former rebels who now form part of Libya's security services. Libyan security services have come in for censure following double car bombings that killed two people on the day Muslims celebrated the feast of Eid al-Fitr a week ago in Tripoli and attacks on several Sufi shrines in the past few days.
The criticism has been led by the newly-elected General National Congress, which on Sunday accused the interior ministry's High Security Committee of being lax or even implicated in the destruction of the Sufi shrines. Islamist hard-liners on Saturday bulldozed part of the mausoleum of Al-Shaab Al-Dahman, close to the centre of the Libyan capital.
The demolition came a day after hard-liners blew up the mausoleum of Sheikh Abdessalem al-Asmar in Zliten, 160 kilometres (100 miles) east of the capital.
According to witnesses another mausoleum, that of Sheikh Ahmed al-Zarruq, had been destroyed in the port of Misrata, 200 kilometres (125 miles) east of Tripoli.
Hard-line Sunni Islamists are implacably opposed to the veneration of tombs of revered Muslim figures, saying that such devotion should be reserved for God alone.
The Sufi sect, which practices a mystical form of Islam and has played a historic role in the affairs of Libya, has increasingly found itself in conflict with Qatari- and Saudi-trained Salafist preachers who consider it heretical.
The High Security Committee comprises ex-rebels who fought Moamer Kadhafi's forces last year in a conflict that ended in the dictator's death.