* Factional fighting edges towards centre of Libyan capital
* First air strikes escalate militia warfare
* OPEC member state at risk of being torn apart (Shelling, colour, TV stations taken off air)
By Heba al-Shibani and Ahmed Elumami
TRIPOLI/BENGHAZI, Libya, Aug 19 Libyan militiamen fired rockets into an affluent district of Tripoli early on Tuesday, moving a battle with a rival armed faction closer to the centre of the capital after fighters on one side came under air attack.
Rebel groups who united to topple Muammar Gaddafi in 2011 have since turned their guns on each other, spreading anarchy in oil-producing Libya and raising fears it may become a failed state destabilising the wider North and West African region.
An air force controlled by renegade General Khalifa Haftar were responsible for strikes on Islamist-leaning militia in Tripoli on Monday, one of his commanders said, after weeks of fighting for control of the capital and its airport.
Hours later after nightfall, unidentified militiamen fired Grad rockets into the Hay Andalus and Gargaresh districts, among the most well-to-do in Tripoli, killing three people, residents said. A health ministry official had no casualty figures.
The neighbourhoods, home to the Libyan bourse, elegant cafes and foreign brand outlets such as Nike and Marks & Spencer, had been buzzing with shoppers until recently.
A Reuters reporter saw a furniture shop with a large hole in its showroom from a direct rocket hit. Cafes and residential buildings were also damaged, while power was cut off in much of the capital for the day.
Heavy shelling could be heard also in other parts of the Mediterranean coastal capital until late on Tuesday.
The air attacks escalated a struggle between Islamist and more moderate militias as well as between forces from different cities all vying for power and spoils in the OPEC-member nation.
Tripoli has largely slipped out of control of the government with senior officials working from Tobruk in the far east, where the new parliament has based itself to escape street fighting.
To influence public opinion, an information ministry official said the government had ordered a satellite provider to pull the plug on two TV stations controlled by pro-Misrata groups, which are seen as closer to Islamist political factions.
Libya's government lacks an army and relies on militias for public security. But while militias get state salaries, they report in practice to their own commanders and towns.
The situation in Tripoli has been exacerbated by a separate showdown between Haftar's forces and Islamist militia in the eastern port city Benghazi.
Explosions shook a Benghazi suburb where Haftar's forces and Islamists have been fighting since Monday. Haftar and regular army forces have been trying to wrest back an army camp overran by Islamist militants earlier this month.
At least three people have been killed and eight wounded since Monday, a medic at a local hospital said.
Neither the Zintan nor Misrata militia is believed to have warplanes, while the Libyan state's jet fighters were destroyed or damaged during the 2011 civil war in which NATO warplanes backed up the anti-Gaddafi uprising.
Western powers have said they had no role in Monday's air strikes.
Some Tripoli residents, fed up with daily factional fighting that has disrupted power and food supplies, hope that NATO will intervene again in Libya. (Additional reporting by Ahmed Elumami and Ayman al-Warfalli; Writing by Ulf Laessing; Editing by Mark Heinrich and Crispian Balmer)