The authorities have complete control over the airport,” deputy interior minister Omar al-Khadrawi told journalists in the capital, adding that dozens assailants were arrested, Al Jazeera reported.

He also said that an investigation had been launched to determine the circumstances of Habshi’s disappearance.

The group of ex-rebels called al-Awfea Brigade, from the town of Tarhouna, 80km southeast of the Libyan capital, was demanding the release of their leader whom they said was being held by Tripoli’s security forces, government official said.

Security forces flooded the airport after negotiations broke down, he said.

Tripoli’s security commission, which answers to the interior ministry, said it was not involved with “the disappearance and abduction” and that it has launched an investigation to find out the reason for his disappearance, AFP reported.

The NTC is still struggling to fully integrate many former rebels who fought forces loyal to Muammar Gaddaf and still won’t let their arms down.

The ex-rebels have remained in organised armed brigades, taking it upon themselves to ensure law and order in the absence of fully functional police and armed forces, Al Arabiya reported.

Monday’s assault on Tripoli airport came as Libya prepares to hold elections for a 200-seat constituent assembly by June 19, as pledged by the NTC although an official has told Al Jazeera that the ballot would be delayed until the first week of July at the earliest.

“Praising or glorifying Muammar Qaddafi, his regime, his ideas or his sons… is punishable by a prison sentence,” said the text of the law read out to reporters by officials, Reuters reported.

The ruling National Transitional Council’s judicial committee on Wednesday read out laws including an amended version of one governing formation of political parties, with no mention of the ban, which was announced last week against parties based on religion, tribe or ethnicity.

It said then that the electoral law was put forward to preserve “national unity”.

Libyans vote in June to elect a national assembly for the first time since the overthrow of Muammar Gaddafi. Eighty of the 200 seats will go to political parties, with the rest reserved for independent candidates, according to BBC.

Dozens of parties have launched since then with the intention of contesting the constituent assembly election that the NTC has pledged to to hold elections by June 19.

Registration centers opened throughout the country on 1 May, and voters have two weeks to register.

The NTC has promised to hold elections by the end of June, but Western diplomats say this might slip until later in the summer.

The ruling National Transitional Council’s (NTC) unexpected move was criticized by Islamic oriented parties willing to compete in upcoming elections.

National Transitional Council spokesman Mohammed al-Harizy said the council passed the law governing the formation of political parties on Tuesday evening. “Parties are not allowed to be based on religion or ethnicity or tribe,” he told Reuters.

He stressed that the provision was put forward to preserve “national unity”.

The Muslim Brotherhood, Libya’s most organized political movement, denounced the move.

“This is not democracy,” said Mohammed Gaira, spokesman for the Freedom and Development party founded by the Muslim Brotherhood earlier this year.

“We are a nationalist party, and Islam is our religion. This law is unacceptable and only suits liberals he added,” according to Aljazeera.

He said this would spark controversy in Libya, whose population of six million are almost entirely Muslims.

“This kind of clause is only useful in countries where there exists many religions, not in Libya where most people are religious Muslims,” Sawan told Reuters.

Sawan pointed out that if the law was not reviewed he would challenge it.

Libya’s NTC has already stressed that the country will be run in accordance with sharia law, though the exact place of Islamic law in the legal system will be settled only once a new constitution is written after elections, Aljazeera reports.

Political analysts have predicted the Muslim Brotherhood is likely to emerge as Libya’s most influential and organized force.