Libya's opposition movement launched a new push against Moammar Gadhafi on Friday, calling for mass demonstrations as it seeks to solidify its gains and loosen the longtime leader's grip on the capital.
The government responded by tightening security in the capital, with tanks and checkpoints lining the airport road and security cordons around mosques where protesters might gather. Young armed men, some wearing green bands on their arms in a sign of loyalty to Gadhafi, checked vehicles for weapons.
Foreign mercenaries and Libyan militiamen loyal to Gadhafi have fought fiercely to roll back the uprising against his rule, attacking two nearby cities Thursday in battles that killed at least 17 people. But rebels made new gains, seizing a military air base, as Gadhafi blamed Osama bin Laden for the upheaval.
A Tripoli resident said people in the capital have received messages on their cell phones urging them to launch demonstrations after Friday prayers, and he said he expected thousands to comply despite fear of pro-Gadhafi militiamen who have been deployed on the streets.
The capital's central Green Square was the site of intense clashes earlier in the week between government supporters and protesters.