TRIPOLI, Libya — Col. Muammar el-Qaddafi’s grip on power dissolved with astonishing speed on Monday as rebels marched into the capital and arrested two of his sons, while residents raucously celebrated the prospective end of his four-decade-old rule. Colonel Qaddafi’s precise whereabouts remained unknown and news reports said loyalist forces still held pockets of the city, stubbornly resisting the rebel advance.
In the central Green Square, the site of many manufactured rallies in support of Colonel Qaddafi, jubilant Libyans tore down posters of him and stomped on them. The rebel leadership announced that the elite presidential guard protecting the Libyan leader had surrendered and that their forces controlled many parts of the city, but not Colonel Qaddafi’s leadership compound.
The National Transitional Council, the rebel governing body, issued a mass text message saying: “We congratulate the Libyan people for the fall of Muammar Qaddafi and call on the Libyan people to go into the street to protect the public property. Long live free Libya.”
Officials loyal to Colonel Qaddafi insisted that the fight was not over, and there were clashes between rebels and government troops early on Monday morning.
Explosions and the sound of mortars could still be heard Monday morning and a rebel fighter told Al Jazeera television that pro-Qaddafi forces still controlled 15 to 20 percent of the capital. News reports quoting rebel officials said tanks had emerged from Colonel Qaddafi’s compound and had opened fire. “There haven’t been many silent minutes,” Karen Graham, a British nurse in Tripoli told the BBC, which also reported that loyalist forces had ambushed a column of rebel troops heading toward the city center.
As western leaders joined a chorus of calls for Colonel Qaddafi to step down, NATO and American officials said that the government’s control of Tripoli, which had been its final stronghold, was now in doubt. The European Union said on Monday it had begun planning for a post-Qaddafi era.
Prime Minister David Cameron of Britain, which along with the United States and France played a central role in the air campaign over Libya, said some of the continued fighting in Tripoli was “extremely fierce.” He said Colonel Qaddafi “must stop fighting without conditions” and relinquish all claims to exercize power.
Mahmud Nacua, a Libyan rebel representative in London, told reporters that the insurgents would “look under every stone” for Colonel Qaddafi so that he could be brought to trial, presumably a reference to charges by the International Criminal Court in The Hague, which issued arrest warrants on Monday for Colonel Qaddafi, one of his sons, Seif al-Islam el-Qaddafi, and his intelligence chief in June, accusing them of crimes against humanity.
President Obama said Sunday night that Colonel Qaddafi and his inner circle had “to recognize that their rule has come to an end” and called on Colonel Qaddafi “to relinquish power once and for all.” He also called on the National Transitional Council to avoid civilian casualties and protect state institutions as it took control of the country.
“Tonight, the momentum against the Qaddafi regime has reached a tipping point,” Mr. Obama said in a statement. “Tripoli is slipping from the grasp of a tyrant. The Qaddafi regime is showing signs of collapsing. The people of Libya are showing that the universal pursuit of dignity and freedom is far stronger than the iron fist of a dictator.”
The shocking collapse of the Qaddafi forces appeared to signal the end for one of the world’s most flamboyant and mercurial political figures, the leader of an idiosyncratic government that was frequently as bizarre as it was brutal.
Long a thorn in the side of the West after he took power in a bloodless coup in 1969, Colonel Qaddafi had managed an awkward reconciliation in recent years, abandoning his fledgling nuclear program and paying billions of dollars to the victims of the Pan Am Flight 103 bombing, which was attributed to Libyan agents.
While denying that he actually headed the government, Colonel Qaddafi created a cult of personality that centered on his Green Book, a volume both trivial and impenetrable. His decades of iron-fisted rule have produced a country, analysts say, that is devoid of credible institutions and any semblance of a civil society — a potential source of trouble in the months and years ahead.
Kareem Fahim reported from Tripoli, and David D. Kirkpatrick from Zintan, Libya. Eric Schmitt contributed reporting from Washington, Mark Landler from Vineyard Haven, Mass., and Alan Cowell from Paris.