The BBC's Jon Leyne: "The only loyal supporters now shown on state TV are in Tripoli"
Libyan ruler Col Muammar Gaddafi is battling to retain control of Tripoli and areas in western Libya as protesters consolidated gains in the east and foreigners continued to flee.
Much of the capital is deserted as pro-Gaddafi gunmen roam the streets, with reports of uprisings in western towns such as Misurata, Sabratha and Zawiya.
Masses of protesters have been celebrating success in eastern towns.
Thousands of foreigners continue to leave, with chaos at Tripoli airport.
At least 300 people have died in the country's uprising.
'Many deaths'
An eyewitness in Tripoli said that the city was virtually closed, with many people hoping protesters and defecting soldiers would arrive from the east to help them.
A text message had been sent out by government officials telling civil servants and other workers to return to their jobs but many people are too scared to go on to the streets.
One Tripoli resident said: "I hope residents don't go to work - this can be our way of a peaceful protest - we will all stay at home indefinitely."
There were reports of gunmen opening fire on Tuesday morning on a queue of people at a bread shop in the Fashloum district, where there has been a heavy military crackdown, with three people killed.
Two naval gunships are reported to have been deployed facing the city.
One Tripoli resident told the BBC: "Anti-government protesters have disappeared. The streets are quiet. There are many, many deaths."
The resident also said doctors were reporting gunmen shooting people in hospitals.
Information from Libya is currently difficult to verify and reports cannot often be independently confirmed.
The BBC's Paul Danahar on the Tunisian border says unconfirmed reports suggest several towns between the border and Tripoli are now held by the anti-government forces but the roads in between are held by people loyal to Col Gaddafi.
Troops are said to have been sent to Sabratha after demonstrators burned government buildings, according to the Quryna news website.
The pre-Gaddafi Libyan flag was also reportedly raised in Zawiya, 50km (30 miles) west of Tripoli while other unconfirmed reports said protesters had seized control of Misurata, 200km east of Tripoli, after days of fighting.
He said one Tunisian man who crossed from Libya told him there was no law in the country and added: "God help them".
Col Gaddafi has vowed to crush the revolt and die as a martyr. His televised speech on Tuesday referred to the protesters as rats and cockroaches and has been greeted with a mixture of anger and mockery.
In the east, thousands of people celebrated on the streets of Benghazi, waving the pre-Gaddafi flags and handing out food and drink.
Protesters are said to be in control of cities from the Egyptian border to Ajdabiya, 800km east of Tripoli.
Quryna reported that a Libyan fighter plane had crashed near Ajdabiya after the two pilots refused to bomb Benghazi and ejected.
At the Egyptian border, sprayed graffiti read: "Welcome to the new Libya".
Many defence committees of residents and defecting military have been set up, including one to guard the anti-aircraft missile bases outside Tobruk.
"Down with the Tyrant" was scrawled on a building in the town of al-Marja.
Airport chaos
Meanwhile, foreigners are struggling to evacuate the violence-torn country.
One American who reached Vienna on a flight from Libya, Kathleen Burnett, told Associated Press the scene at Tripoli airport was "total chaos", adding: "The airport was mobbed, you wouldn't believe the number of people."
And a Briton airlifted out by the Portuguese told the BBC he knew of dozens who were trying to get to Tripoli airport but were too afraid because of "the soldiers who are out on the streets looting and plundering".
One Air Malta pilot who was evacuating Maltese from Tripoli airport said he had to go into the terminal to round up passengers.
He said he saw people fighting to get on to a plane.
Briton Chris Murphy and his wife said they had also "fought their way" through crowds to get on their flight but the plane had about 100 empty seats.
Many countries have been trying to evacuate their citizens.
Many Libyans have been setting up defence committees
France, Turkey and Russia are among the nations that have sent planes and frigates to pick up thousands of their stranded nationals.
Italian Foreign Minister Franco Frattini told reporters in Rome he feared an immigrant exodus on a "biblical scale" if Col Gaddafi was toppled, predicting up to 300,000 Libyans could flee.
Col Gaddafi is also facing increased internal and international diplomatic pressure.
The man considered the colonel's number two, Interior Minister Abdel Fattah Younes al-Abidi, is among senior figures who have joined the opposition.
The UN Security Council demanded an end to the violence on Tuesday, while the Arab League suspended Libya.