(CNN) -- Fighting battered the besieged seaside city of Misrata Tuesday as bombs -- presumably from NATO warplanes -- shook the ground after pro-government forces launched what rebel officials said was their most aggressive attack so far on the port.
Shells detonated near a refugee camp in the port area, where thousands of migrants have been housed while they await ships to carry them to safety. Witnesses said three people were killed and several were wounded.
A Misrata port security officer told CNN shelling on the wider Misrata port means that "refugees located between the steel port and the main port have been targeted."
The attacks by forces loyal to Libyan leader Moammar Gadhafi underscored the falsity of government officials' claims that they had suspended military operations in the city.
A CNN crew saw plumes of smoke rising from beyond the Misrata port, and another TV crew said it had seen fire in the distance "earlier."
But Misrata residents told CNN that the smoke and fire were coming from the town of Tawargha, 21 miles from the port. The residents added that Gadhafi troops were positioned in the area of Tawargha.
Jean Michel Monod, who heads the International Committee of the Red Cross delegation in Tripoli, said a ship that was in Misrata to pick up foreigners departed earlier than anticipated in the morning because shelling was close to the port.
He said the ICRC would have liked to take on a few more than the approximately 630 people whom it did take.
Street fighting and confrontations between pro- and anti-government forces erupted in Misrata's suburbs and pro-Gadhafi forces struck the city from miles away, a witness said.
However, the witness said, the city center was calm. There was no street-to-street fighting in the urban cauldron and Tripoli Street, the city's main boulevard, was clear, the witness said.
Misrata has been the scene of deadly battles as rebels have sought to oust Gadhafi, who has been in power for more than four decades.
Hundreds of people have been killed in the battle for the city, which has been under siege by Gadhafi's forces for seven weeks. The city's population of about 450,000 makes it the country's third-largest.
"As fighting continues to rage in Misrata, the families recently evacuated by boats to Tobruk from the embattled city describe a catastrophic situation with many having lived in fear of indiscriminate shelling," the U.N. High Commissioner for Refugees said Tuesday. "Many houses and buildings have been destroyed and some families had to move several times."
The U.N. refugee agency said parts of the city have lacked electricity and water and people have been hiding in their homes for two months "before seizing the opportunity of a lull in fighting to get to the harbor and board a boat."
"Sniper fire, street clashes and shelling have prevented people from venturing outside of their homes to get food and medicine," the agency said.
"In some neighborhoods in Misrata, pregnant women gave birth in their homes as it would have been too dangerous to make the trip to the hospital."
The agency also said that, in recent weeks, some 30,000 Libyan civilians have fled their homes in the western mountain region for Tunisia.
In New York, U.N. Secretary-General Ban Ki-moon credited NATO's actions with having saved many lives. "It's also clear that the Libyan regime has lost both legitimacy and credibility, particularly in terms of protecting its people and addressing its legitimate aspirations for change," Ban told reporters. "The Libyan people want to determine their own political future; they must be given the chance to do so."
He said diplomatic efforts focused on securing a cease-fire and achieving a political solution, and said his special envoy will return Friday to Benghazi.
NATO is leading an international military operation in Libya that includes air-strikes targeting Gadhafi's military resources. It is operating under a U.N. Security Council resolution authorizing all means necessary to protect civilians.
State-run Libyan TV reported that "Libya officially calls on Russia to ask for an extraordinary session by the Security Council to discuss the continuation of the crusader colonial aggression in bombing Libyan civilian locations and its attempt to target the leader Moammar Gadhafi ... violating the two council's resolutions and the international conventions and laws."
In Copenhagen, Denmark, Russian Prime Minister Vladimir Putin criticized the Western coalition.
He said that, at its inception, the coalition didn't want to kill Gadhafi, but some officials have since acknowledged that he is a target.
"At first, they spoke about the need to close the air space. All right, but how does that correspond with bombings of Gadhafi's palaces every night?" he asked. "They say they don't want to eliminate him. But why are they bombing his palaces then?"
He also said he dislikes the relentless pounding of a small country and the destruction of its infrastructure.
"Initially there was talk about imposing a no-fly zone. But now we're seeing the country's entire infrastructure being destroyed, and one of the warring sides is now advancing, protected from air. This can go on and on forever," said Putin.
"I think that we should act within the framework of international law, understanding our responsibility and with care towards the civilian population."
U.S. National Security Council spokesman Tommy Vietor reiterated Tuesday that NATO's mission is to enforce "the arms embargo, no-fly zone and conduct a civilian protection mission," but it's not regime change.
"As part of that mission, the coalition has targeted command-and-control sites that are being used by regime forces to wage attacks against Libyan civilians -- brutal attacks that this week alone have reportedly killed dozens of civilians in Misrata alone. In fact, the degradation of those sites is part of the reason the opposition has had increased success in pushing Gadhafi's forces out of Misrata in recent days. There is no change in U.S. policy regarding assassination."
British Foreign Secretary William Hague, briefing the House of Commons on NATO's operation in Libya, said "the case for action remains compelling" and that Gadhafi has shown "he has no regard for civilian lives."
"By his actions it is clear that Gadhafi has no intention of observing the conditions in Security Council Resolution 1973 that I described to the House earlier this month," Hague said. "He has repeatedly ignored the cease-fires that he himself has announced. Our military action is defined by the U.N. Security Council resolutions. We are also clear that Gadhafi should go and it is impossible to see a viable or peaceful way forward for Libya until he does so."
Hague said diplomatic, economic and military pressure against the Gadhafi regime has been successful. He said military action has "seriously degraded" Gadhafi forces and they remain unable to enter Benghazi, where the opposition is based.
CNN's Raja Razek, Reza Sayah, Saad Abedine and Joe Sterling contributed to this report.