BENGHAZI, Libya — The scope of Moammar Gadhafi's control was whittled away Wednesday as major Libyan cities and towns closer to the capital fell to the rebellion against his rule. In the east, now all but broken away, the opposition vowed to "liberate" Tripoli, where the Libyan leader is holed up with a force of militiamen roaming the streets and tanks guarding the outskirts.
In a further sign of Gadhafi's faltering hold, two air force pilots — one from the leader's own tribe — parachuted out of their warplane and let it crash into the eastern Libyan desert rather than follow orders to bomb an opposition-held city.
International momentum was building for action to punish Gadhafi's regime for the bloody crackdown it has unleashed against the uprising that began Feb. 15.
President Barack Obama said the suffering and bloodshed in Libya "is outrageous and it is unacceptable," and he directed his administration to prepare a full range of options, including possible sanctions that could freeze the assets and ban travel to the United States by Libyan officials.
French President Nicolas Sarkozy raised the possibility of the European Union cutting off economic ties.
Another proposal gaining some traction was for the United Nations to declare a no-fly zone over Libya to prevent it using warplanes to hit protesters. U.N. High Commissioner for Human Rights Navi Pillay said that if reports of such strikes are confirmed, "there's an immediate need for that level of protection."
Franco Frattini, the foreign minister of Italy — the former colonial power with longstanding ties — said there were probably more than 1,000 dead across the country.
After a long and defiant televised speech by Gadhafi on Tuesday, in which he vowed to hunt opponents "house by house," thousands of his supporters converged on Green Square in central Tripoli, brandishing large machetes.
Many loaded into trucks headed for the outlying areas of the city, where they occupied traffic intersections and appeared to be massing for neighborhood-to-neighborhood searches.
The New York Times reported that groups of heavily armed militiamen and mercenaries from other African countries cruised the streets in pickups, spraying crowds with machine-gun fire and then carting away bodies in vans.
Protest organizers called for new rallies today and Friday, raising the potential for a more bloody confrontation in Tripoli.
Gadhafi's residence at Tripoli's Aziziya Gates was guarded by loyalists along with a line of armed militiamen in vehicles, some masked, while tanks were deployed on the city's eastern outskirts.
But below the surface, protesters were organizing. At night, they fan out and spray-paint anti-Gadhafi graffiti or set fires near police stations.
In opposition-controlled Benghazi, the eastern city where the uprising began, residents held a mass rally outside the city's main courthouse, vowing to support protests in the capital, said Farag al-Warfali, a banker. Afterward, young men went into the courthouse to register to obtain weapons, which had been looted from police stations and military bases and then turned over to the city's new rulers, he said.
The idea is to "take their weapons and march toward Tripoli," al-Warfali said, although Benghazi lies 580 miles east of the capital, and territory still loyal to Gadhafi lies between them.
The extent of Gadhafi's control over the country he has ruled for 41 years had been reduced to the western coastal region around Tripoli, the deserts to the south and parts of the center.
Though the Libyan revolt began with a relatively well organized core of longtime government critics in Benghazi, its spread to the capital was swift and spontaneous, outracing any efforts to coordinate the protests.
Gadhafi has lashed out with a level of violence unseen in other uprisings, partly by importing foreigners without ties to the Libyan people. His idiosyncratic one-man rule has left the country without any national institutions that could tame his retribution or provide the framework for a transitional government.
Many analysts have suggested that Gadhafi seemed to fear the development of any national institutions or networks that might check his power, and he has kept even his military divided into battalions, each loyal mainly to its own officers.
That has set the stage for heavy defections during the revolt. But it also means that Libya's military is unlikely to play the stabilizing role its Tunisian or Egyptian counterparts did.
At the Egyptian border, guards had fled, and local tribal elders have formed local committees to take their place.
A defense committee of residents was even guarding one of Gadhafi's highly secretive anti-aircraft missile bases outside Tobruk. "This is the first time I've seen missiles like these up close," said Abdelsalam al-Gedani, one of the guards carrying a Kalashnikov.
International alarm has risen over the crisis, and is sending oil prices soaring and European and other countries scrambling to get their citizens out of Libya. Oil prices hit $100 per barrel for the first time since 2008. Libya is the world's 15th largest exporter of crude, accounting for 2 percent of global daily output.
Information from the New York Times contributed to this report.