Skepticism over the military campaign is growing as weeks of airstrikes have failed to unseat Libyan leader Moammar Gadhafi and outrage rises over allegations that airstrikes have caused civilian casualties.
The air campaign continued Wednesday. At least two explosions shook Tripoli before noon as fighter jets soared overhead. It wasn't immediately clear what had been hit or if there were casualties.
In Rome, the Italian foreign minister called for a suspension in fighting so aid corridors could be set up.
"The humanitarian end of military operations is essential to allow for immediate aid," including in areas around Tripoli and the rebel stronghold of Misrata, Foreign Minister Franco Frattini said.
Frattini also expressed concern over civilian casualties, referring to "dramatic errors" in the bombing campaign.
"With regard to NATO, it is opportune to ask for more detailed information on results" in the attacks, he said in comments to a parliamentary commission.
Italy is Libya's former colonial ruler and maintains strong commercial ties to the country. Italy is participating in the NATO-led campaign by allowing use of its air bases to coalition partners and its own aircraft for missions.
Frattini's comments come three days after Premier Silvio Berlusconi's key political ally, Northern League leader Umberto Bossi, called for an end to Italy's participation in the Libyan war.
The League, which is heavily anti-immigrant, has been vehemently opposed to the war because of fears it would unleash waves of refugees on Italy's shores. Some 20,000 people have arrived in Italy in recent months following unrest in Libya and Tunisia.
A coalition including France, Britain and the United States began striking Gadhafi's forces under a United Nations resolution to protect civilians on March 19. NATO assumed control of the air campaign over Libya on March 31. It's joined by a number of Arab allies.
In London, British Prime Minister David Cameron insisted that the NATO-led alliance was "holding strong," and would complete its task in Libya.
"When you look at what's happening in Libya, where you see a strengthening of the revolt in the west of Libya, you see more people deserting Gadhafi's regime," Cameron told lawmakers in the House of Commons. "You see growing unpopularity in his regime and indeed our coalition holding strong, I think time is on our side, the pressure is growing and I believe we will take it to a satisfactory conclusion."
Cameron's office said Britain would not support Frattini's call for a halt to the air campaign to allow access for humanitarian aid.
"We are very clear that the right approach at the current time is to increase the pressure on Gadhafi's regime," Cameron's spokesman Steve Field told reporters. He said there was no evidence that aid wasn't reaching civilians.
Britain fears that any pause in the campaign could allow Gadhafi's forces to regroup and launch new offensives against civilians.
Despite questions raised over the impact of the campaign on stretched defense resources, and worries over civilian casualties, Cameron said the U.K. was "capable of keeping up this operation for as long as it takes."
The Libyan regime has accused the alliance of targeting civilians — a charge NATO rejects.
NATO acknowledged it may have struck a residential building and caused civilian casualties in Tripoli earlier this week. It also hammered a compound belonging to a close Gadhafi associate, Khoweildi al-Hamidi, and killed what Libya says was 19 people, including at least three children. NATO called that target a "command and control" center and said it regrets any civilian deaths caused by the strike.
More than a thousand mourners gathered near the compound outside the town of Surman, some 40 miles (60 kilometers) west of Tripoli on Wednesday to bury those killed in Monday's intense bombing. Al-Hamidi attended the funeral, carrying aloft framed portraits of two grandchildren killed in the strike.
"People are feeling very bitter, angry and sad that this had to happen in the first place," Libyan government spokesman Moussa Ibrahim told reporters at the funeral. "This conflict has to come to an end immediately."
Rebels fighting Gadhafi's forces have taken over much of the eastern half of the country. They also control pockets in the west, including the vital port city of Misrata, about 125 miles (200 kilometers) from Tripoli.
Rebel forces facing barrages of rockets and mortars launched by government troops are trying to push their front line forward from Misrata toward the capital. But an increased number of rockets have been hitting closer to Misrata this week, raising fears among rebels of a renewed push by Gadhafi's forces toward the city.
A hospital official said Wednesday that two people had been killed and two wounded in fighting in Dafniya, some 15 miles (25 kilometers) west of Misrata. Three rockets also struck near the port east of Misrata, but they hit a field and caused no injuries.
The rebels appear to be attracting more international support.
China told Libyan rebel leader Mahmoud Jibril on Wednesday that his Transitional National Council represents a growing segment of the Libyan public and is becoming a major political force in the country.
The comments by Chinese Foreign Minister Yang Jiechi were the country's strongest endorsement yet of the rebel council. Beijing, an important business partner with Libya, says it isn't taking sides in the more than 4-month-old conflict.
Also on Wednesday, Danish Foreign Minister Lene Espersen made a surprise visit to the rebels' de facto capital of Benghazi in eastern Libya to offer support for the rebels' transitional government.
"We recognize the National Transitional Council through the transitional period," she told reporters. "The Danish parliament wants to continue support of the Libyan cause and that is including military support and the political help including recognizing the NTC."
Stringer was reporting from London. Associated Press writers Hadeel al-Shalchi in Misrata and Alessandra Rizzo in Rome contributed to this report.