Libyan police fired tear gas at protestors demonstrating against Moammar Gadhafi's regime in Tripoli Friday as rebel fighters in eastern Libya tried to push the front line nearer to the capital.

Some 100 anti-Gadhafi demonstrators clashed with police in the Tajoura neighborhood in eastern Tripoli after Friday prayers, a witness said, while another said opponents and supporters of the regime traded blows near the capital's Green Square.

Forces loyal to Libyan leader Moammar Gadhafi were battling rebels on Friday for control of the town of Zawiyah, near Tripoli, in heavy fighting that has left "many dead," witnesses said.

State television said Gadhafi's forces had wrested control from the rebels of the middle-class dormitory town 60 kilometers west of Tripoli but a government official said "pockets of resistance" remained.

Interpol has issued a global alert against Libyan leader Moammar Gadhafi and 15 others, including members of his family and close associates, the global police organization said on Friday.

Interpol said it issued the Orange Notice "in a bid to warn member states of the danger posed by the movement of these individuals and their assets," following a U.N. Security Council travel ban and asset freeze.

Thousands of protesters massed in cities and towns across Iraq after streaming in on foot on Friday in defiance of vehicle bans for rallies over corruption, unemployment and poor public services.

The demonstrations were markedly smaller than similar protests which took place in more than a dozen cities a week ago, spurring Prime Minister Nouri al-Maliki to give his cabinet 100 days to shape up or face the sack.

Yemeni soldiers killed four protesters and wounded seven others on Friday when they opened fire on an anti-regime rally in the northern province of Amman, officials and Shiite rebels said.

The shooting, which came a day after the opposition and clerics offered embattled President Ali Abdullah Saleh a smooth exit from power, took place in the village of Semla, 170 kilometers from the capital Sanaa.

Libyan forces carried out an air strike on the edge of the rebel-held town of Ajdabiya Friday, as opponents of veteran leader Moammar Gadhafi called for fresh protests in the capital Tripoli.

U.S. President Barack Obama said all options were on the table for driving Gadhafi out of power as the strongman's son said air strikes on rebel-held positions were scare tactics rather than to inflict serious damage.

Interim Tunisian President Foued Mebazaa on Thursday announced that a constituent assembly charged with developing a new post-revolt constitution will be elected on July 24.

"We declare today the start of a new era ... in the framework of a new political system that breaks definitely from the deposed regime," Mebazaa said in a televised address to the nation.

U.S. President Barack Obama said Thursday he is examining the "full range" of military options, including a no-fly zone, if the revolt in Libya turns into a bloody stalemate and humanitarian disaster.

Accusing Moammar Gadhafi of encouraging violence against his citizens, Obama again called on the Libyan leader to stand down for the good of his country.

The Libyan opposition on Thursday flatly rejected a mediation proposal by Venezuelan President Hugo Chavez to find a peaceful solution to the crisis in the country, a spokesman said.

"We have a very clear statement. It's too late. Too much blood has been spilt," Mustafa Gheriani, a spokesman for the opposition's self-declared national council set up in the eastern city of Benghazi, told Agence France Presse.

The U.S. military is not opposed to imposing a no-fly zone over Libya, the Pentagon said on Thursday, despite a stream of skeptical comments by defense leaders.

The caution expressed by Defense Secretary Robert Gates and senior officers over a potential no-fly zone or other military action "should not be interpreted as somehow an opposition to doing this," Pentagon press secretary Geoff Morrell told MSNBC television.