The vast majority of Tripoli's public and private sectors went on a general strike on Sunday to force Libya's government to drive out militiamen blamed for clashes that killed at least 45 people.
The streets of Tripoli were deserted as the city's businesses and schools were closed but shops like pharmacies, hospitals and gas stations remained open.
The call was made by the city's leaders, who urged all militias to leave the capital to allow "the government, the police and the army" to work.
Al-Sadat al-Badri, head of Tripoli's city council, said that the strike would last for three days, if their demands were not met.
"We have declared a strike for three days from today, but if our demands are not met we will continue," he said. "We will not negotiate with them. Things are as clear as the sun, we want a decision."
Armed residents set up checkpoints and barricades of metal, wood and tires to protect their neighbourhoods throughout the city, fearing renewed violence.
Intelligence chief kidnapped
Mustafa Noah, Libya's deputy intelligence chief, was kidnapped outside Tripoli International Airport after he returned on a flight from Turkey on Sunday, security sources said.
"The vice president of intelligence was abducted shortly after his arrival in Tripoli from a trip abroad," said the official, who declined to be named.
Noah, the head of intelligence agency's espionage unit, was pulled into a vehicle in the carpark, and had no bodyguards with him at the time, one of the sources said.
No group claimed responsibility for the abduction so far, but militias have kidnapped officials in the past to get political leverage. Prime Minister Ali Zeidan was abducted by a government-payrolled militia group last month, but was freed unharmed after a few hours.
Libya's state news agency LANA said on Sunday that the Misrata militia, accused of being responsible for Friday's killing, had abandoned its headquarters in the southern Tripoli neighbourhood of Gharghour.
Late on Saturday, a government-affiliated militia, the Libya Shield-Central Command, said it was in control of Gharghour and vowed to turn it over to the government.
Violence broke out on Friday when militiamen from the coastal city of Misrata opened fire on protesters marching on their brigade quarters in Tripoli to demand they leave the capital.
Dozens of people were killed in the clashes that followed – the deadliest street fighting in Tripoli since the fall of longtime dictator Muammar Gaddafi in 2011. Misrata gunmen and rival militias clashed again on Saturday to the east of the capital, killing one more person.
Many militias have turned villas and residential compounds of former Gaddafi-era officials into camps where they stockpile weapons, carving out zones of power, defying the state authority and launching violent attacks.
The government has tried to incorporate them into the police force and army but has failed so far.