As Gaddafi forces launch a bloody new assault on rebel strongholds, new reports show a complete disruption in Internet service across the country. Plus, full coverage of the uprising.

Protests returned to the seat of Muammar Gaddafi’s power Friday, with protesters taking to the streets of Tripoli after Friday afternoon prayers. They were attacked with tear gas, and the violence appears to be worse in other parts of the country. Meanwhile, the country has gone dark, with Internet access completely shut off across the whole nation shortly after 4:35 p.m. on Thursday.

Libya’s opposition has thus far held off loyalist militias in Zawiya, a key city 30 miles from Tripoli. (See map below.) But Gaddafi’s mercenaries made another attempt Friday to retake Zawiya, and the clash was bloody: At least 50 people were killed, one witness told Reuters. Thirty of those were civilians, and the city’s hospitals are full of the injured. “They could not find a space for the casualties,” a second witness said. There was also fierce fighting in Ras Lanuf, and police in Tripoli fired tear gas on peaceful protesters and killed those who fell to the ground wounded. On Friday, the U.S. stepped up its humanitarian aid to the country, sending two military planes full of emergency supplies to neighboring Tunisia.

In one district of Tripoli, protesters burned Libyan flags and called for Gaddafi’s fall while pro-Gaddafi forces fired tear gas. Authorities had been gearing up for the Friday protest by reportedly closing mosques and detaining people overnight. Residents say pro-Gaddafi militias have been roaming the streets in civilian cars, detaining and killing people and leaving their bodies in the street. Meanwhile Gaddafi forces made their second air raid on the rebel-held harbor of Breqa, and rebel forces advanced on the oil port of Ras Lanuf. Plus, more on Libya.

WATCH THE VIDEO (Warning: Graphic)

"People can't retrieve one of the dead bodies"

LPC from Az Zawiya: "People can't retrieve one of the dead bodies because #Gaddafi forces are shooting at them from a roof." #Libya #Feb17less than a minute ago via webFeb 17 voicesfeb17voices

"50+ dead, 300 injured during the massacre of Zawiah today"

CONFIRMED on Al Jazeera: 50+ dead, 300 injured during the massacre of Zawiah today #libya #feb17 @ FreeLibya @ feb17libya @ IbnOmar2005less than a minute ago via web.N_Benghazi

"Massacre today in Az Zawiya"

An audio report allegedly details the "massacre" in Az Zawiya. Listen: