TRIPOLI, Libya — The International Criminal Court’s chief prosecutor sought arrest warrants yesterday for Libyan leader Moammar Khadafy, his son, and the country’s intelligence chief on charges of authorizing the killing of civilians in a crackdown on antigovernment rebels.

Khadafy’s government denied the allegations.

The call for the inquest was the first such action in the Netherlands-based court linked to the Arab uprisings. It opened another potential front against Khadafy’s regime even as the autocratic leader stands firm against widening NATO airstrikes and rebels with growing international backing.

At least two explosions could be heard in Tripoli early today, indicating more NATO airstrikes. It was not immediately known what was targeted or whether there were any casualties. The sound of sporadic gunfire could be heard in downtown Tripoli.

NATO has stepped up its airstrikes in Tripoli in an apparent attempt to weaken Khadafy’s stronghold and potentially target the leader himself.

In a separate development, Libyan spokesman Moussa Ibrahim said late yesterday that four reporters held for the past few weeks by the Libyan government, including two Americans, will face trial and probably will be released. The reporters, who will appear before a judge in an administrative court today, are expected to be fined and then released, Ibrahim said.

Two Americans — New Hampshire native James Foley, a photojournalist working for the Boston-based foreign news website GlobalPost; and Clare Morgana Gillis, who was covering the fighting for The Atlantic and USA Today — are being detained in Libya, but it was not immediately clear whether Ibrahim was referring to them.

The international warrants could further isolate Khadafy and his inner circle and potentially complicate the options for a negotiated settlement. But they also could harden Khadafy’s resolve to stand and fight, since the legal action has been seen in Libya as giving NATO more justification to go after him.

Because the United Nations Security Council ordered the ICC investigation, UN member states would be obliged to arrest him if he ventured into their territory.

Prosecutor Luis Moreno-Ocampo said he was seeking warrants against Khadafy, his son Seif al-Islam Khadafy, and intelligence chief Abdullah al-Sanoussi on charges of ordering, planning, and participating in illegal attacks. The younger Khadafy has become one of the public faces of the regime through frequent interviews with the media.

Moreno-Ocampo said he had evidence that Khadafy’s forces attacked civilians in their homes, shot at demonstrators with live ammunition, shelled funeral processions, and deployed snipers to kill people leaving mosques.

Judges must now evaluate the evidence before deciding whether to confirm the charges and issue international arrest warrants.

Asked why he has not launched similar investigations into other Arab uprisings, Moreno-Ocampo said that no such action had been requested by the Security Council, as was the case of Libya.

Regimes in Egypt and Tunisia — which eventually were overthrown — were accused of human rights violations in their efforts to end street demonstrations. Similar charges have been leveled at the rulers of Bahrain, Yemen, and Syria.

In London yesterday, a British defense minister, Nick Harvey, told legislators he believed it was likely the court would seek to charge Syrian President Bashar al-Assad over his government’s violent crackdown on protests.

He said the court was “highly likely to arrive at a similar conclusion’’ in the case of Assad as it had with Khadafy.

Ibrahim told reporters in Tripoli that the regime would pay no attention to arrest warrants that could be issued against Khadafy or the others, saying the prosecutor relied on faulty media reports and “reached incoherent conclusions.’’

In the eastern city of Benghazi, headquarters for the opposition movement, rebel spokesman Abdel-Hafidh Ghoga said the rebels welcomed the ICC case.

“It is these three individuals who are primarily running the campaign for genocide of the Libyan people and the criminal activities that have taken place so far,’’ he said at a news conference.

He said, however, that the opposition would like to see Khadafy tried first in Libya, then before the world body.

Under Khadafy’s more than four decades in power, the regime “has committed many crimes against the Libyan people, and the Libyan people want to see him punished for that,’’ Ghoga said.

In Brussels, NATO is discussing what additional facilities under Khadafy’s control could be targeted under Security Council resolutions.

© Copyright 2011 Globe Newspaper Company.