The U.S. government tightened sanctions against three Libya-controlled banks in Turkey, Tunisia and Lebanon on Tuesday, ratcheting up the pressure on leader Moammer Gadhafi's support.

The U.S. Treasury Department said it had targeted three foreign Libyan-owned banks, identified six additional companies subject to sanctions, and lifted sanctions against a former Libyan oil minister who defected from the Gadhafi regime last month.

The army of Moammar Gadhafi has laid land mines in Libya's Nafusa Mountains to counter rebel attacks there, Human Rights Watch said on Tuesday.

The mountains, which lie to the south of Tripoli, have been the site of clashes between the two sides, as the rebels attempt to edge toward the capital.

A major Libyan civil society conference set to be held in Rome this weekend and planned to include tribal representatives has been delayed indefinitely, the Italian foreign ministry said on Tuesday.

"The dates are still being defined. It won't be this weekend," a ministry spokesman told Agence France Presse. The spokesman said the meeting organized by opponents to Libyan leader Moammar Gadhafi plans to represent "all of Libyan society."

Italy's foreign minister warned Monday that NATO's accidental killing of civilians in the Libyan air war was endangering the alliance's credibility.

"NATO's credibility is at risk," Franco Frattini told reporters on the sidelines of a meeting of European Union foreign ministers in Luxembourg.

Libyan officials showed reporters five bodies, two of them of toddlers, they said were among nine civilians killed in a "barbaric" NATO air raid Sunday, as pressure mounted on the alliance to allow a political solution.

Government spokesman Moussa Ibrahim accused the Western alliance of "deliberately targeting civilians," insisting there were no military targets anywhere near the residential neighborhood of the capital that was hit.

Hours after loud blasts shook Libya's capital Tripoli, Moammar Gadhafi vowed to defeat NATO as his forces launched a deadly rocket assault on rebel-held Misrata.

State television on Friday aired Gadhafi's comments in what it said was a live telephone call from the Libyan leader, who has gone underground since Western nations began waging an air war in March to protect civilians from a bloody protest crackdown.

Libyan rebel chief Mahmoud Jibril denied Friday suggestions by a Russian envoy that the insurgents had been negotiating with Moammer Gadhafi's regime.

"I can assure you there is and there was no negotiation between the NTC and the regime," the head of the rebel National Transitional Council told a press conference in Naples.

Two loud blasts shook Libya's capital Tripoli on Friday afternoon following a series of more distant explosions heard earlier in the day, an Agence France Presse journalist said.

Tripoli has been targeted anew by NATO warplanes, which since Thursday have been constantly overflying the Libyan capital.

Russia's special envoy Mikhail Margelov said he had been told by Libya's prime minister Thursday that Tripoli was holding talks with the Benghazi-based rebels in Paris, Russian news agencies reported.

But he cautioned that the talks, whose latest round he said was held this week in Paris, were off to a slow start because of the "tough positions" adopted by the two sides.

Russia and China oppose outside interference in the unrest in the Arab world, the two presidents said Thursday in a declaration, as the West seeks their support in increasing pressure on Syria.

"The sides believe that the search for settling the situation in the countries of Middle East and North Africa should take place in the legal field and through political means," said the declaration signed by Presidents Dmitry Medvedev and Hu Jintao.