A Turkish humanitarian ship carrying more than 250 injured people from the Libyan city of Misrata has arrived in the rebel stronghold of Benghazi.
Misrata, the only city in the west still controlled by the rebels, has been under siege by forces loyal to Col Muammar Gaddafi for several weeks.
Doctors on board the ship said many people had extremely serious injuries.
Meanwhile, the eastern oil town of Brega has seen continued fighting between rebels and pro-Gaddafi forces.
A BBC correspondent says an uneasy stalemate is developing.
Government troops are reported to be holding ground near its university, but are reluctant to engage rebels because of the risk of Nato air strikes.
The poorly armed and disorganised rebel forces are unable or unwilling to push on towards Brega and are calling for more help from the West.
Libya's Deputy Foreign Minister, Abdul Ati al-Obeidi, has told the Greek prime minister that Col Gaddafi wants the fighting to end.
"From the Libyan envoy's comments it appears that the regime is seeking a solution," Greek Foreign Minister Dimitris Droutsas told reporters.
Mr Droutsas said Athens had stressed the international community's call for Libya to comply with UN Security Council resolution 1973, which authorised military intervention to protect civilians.
The Libyan envoy would be going on to Turkey on Monday and then Malta to continue his diplomatic contacts, he added.
Turkey's Foreign Minister, Ahmet Davutoglu, ordered the Ankara, a car ferry that had been turned into a makeshift hospital, into Misrata on Sunday after it had spend four days waiting for permission to dock.
The ship, which was also carrying medical supplies for doctors in Misrata, arrived under cover from 10 Turkish F-16 fighter jets and two navy frigates, Turkish consular official Ali Akin told the Reuters news agency.
With heavily armed Turkish police special forces standing by, the injured people were taken aboard and laid on mattresses on one of the car decks, above which saline drips were hung. Some were accompanied by their relatives.
Mr Akin said the ship had to leave early after a large crowd - including hundreds of Egyptians - pressed forward on the quayside hoping to escape.
The BBC's Jon Leyne, who went on board the Ankara, says many of the patients have extremely serious injuries, including some amputations.
One man lost part of his leg in an explosion as he was taking his wife into hospital for treatment. A 13-year-old boy described how he was shot by a sniper. A 12 year old was peppered with shrapnel when a rocket exploded near him when he and his brother were on their way to the market.
Mohammed Muftah, who had shrapnel wounds on his legs, back and neck, said Col Gaddafi's troops had "killed entire families".
"I have a neighbour who lost his wife and his three children," he told the AFP news agency. "They did it just to terrorise people."
Our correspondent says everyone had stories of the ever worsening conditions in Misrata. They told him that much of the city had no water or electricity and no-one was safe from shelling or sniper-fire.
"It is very, very bad. In my street, Gaddafi bombed us," Ibrahim al-Aradi, who had wounds in his groin, told Reuters. "We have no water, no electricity. We don't have medicine. There are snipers everywhere."
Doctors on board say medical care conditions Misrata were inadequate, and that more than 200 people had been killed and hundreds more wounded. One unconfirmed report said 160 may have died this week.
At least one person was killed and several wounded early on Sunday when government forces shelled a building in Misrata, a resident told Reuters.
As the ship arrived in Benghazi several hundred rebel supporters waiting on the quayside chanted: "The blood of martyrs is spilled for freedom."
The Ankara would pick up about 100 more wounded before setting sail for the Turkish port of Cesme, where the casualties would be treated in a well-equipped, well-supplied, modern hospital, officials said.
To the east of Benghazi, government troops continued to hold ground near the university in Brega, trading rocket and artillery fire with the rebels.
The rebel Transitional National Council has appealed for new Nato air strikes, as well as weapons and military training to be provided by foreign governments.
They have acknowledged that rebel fighters firing in the air through lack of discipline could have provoked the Nato air strike on a rebel convoy on Friday, which left at least 13 people dead.
The rebel military commanders say they are trying to bring a new professionalism to its military campaign. Road blocks have been set up close to the frontline and only soldiers with at least some training are allowed through.
Iman Bugaighis, a spokeswoman for the rebel council, told the BBC: "We have reorganised our troops. Now the army is in the front and then followed by our volunteers who are fighting with the army."
Archbishop Desmond Tutu of South Africa meanwhile called for a swift end to the conflict, even if it meant offering Col Gaddafi safe haven in another country.