Tripoli, Libya (CNN) -- Britain said Tuesday it is expanding its presence in Libya with military advisers and the European Union said it is prepared to send troops for humanitarian assistance if requested by the United Nations.

Plans for increased Western involvement surfaced as Moammar Gadhafi's forces shelled Misrata again Tuesday. Residents and refugees rescued from the city described a terrifying situation in the ravaged western city that continues daily to pay a heavy price in the Libyan war.

"The situation is very dangerous, every day the shelling is increasing," said a resident who was not identified for safety reasons. "They are using more types of weapons, and people are wondering why NATO is not doing anything."

The number of casualties was unclear Tuesday but at least 24 people have already died in Misrata his week, an opposition spokesman told CNN Monday. He said another 113 were injured.

Rebel-compiled figures estimate that more than 10,000 people have been killed so far in the Libyan conflict and more than 55,000 have been injured.

With a humanitarian disaster looming, the EU said it is ready to respond, but not without the blessing of the United Nations.

An EU official, who asked not to be identified, said it is unclear how many troops would be deployed, though he said the number would be "definitely less than 1,000."

The Council of the European Union agreed to the operation -- called EUFOR Libya -- earlier this month. If requested, EUFOR Libya would "contribute to the safe movement and evacuation of displaced persons" and support humanitarian agencies in their activities, the council said in a written statement.

And Britain said it is sending a contingent of experienced military officers to the rebel stronghold of Bengazhi in an advisory role.

The team will work with Libya's Transitional National Council on how the opposition can improve military organizational structures, communications and logistics, the British Foreign Office said. It will also assist in the delivery of critically needed aid.

"This deployment is fully within the terms of UNSCR 1973 both in respect of civilian protection and its provision expressly ruling out a foreign occupation force on Libyan soil," Foreign Secretary William Hague said on Tuesday.

"Consistent with our obligations under that resolution, our officers will not be involved in training or arming the opposition's fighting forces. Nor will they be involved in the planning or execution of the NTC's military operations or in the provision of any other form of operational military advice."

The moves raise questions of whether a greater international military involvement on the ground could emerge.

The Center for Strategic and International Studies' Stephen Flanagan said the British stance is another step up the level of military engagement.

He said he thinks that the British forces are trying to give "more coherence" and "greater capacity" to the efforts of the rebels to provide their own defense and that the alliance is trying to find more ways to keep up the pressure.

But he doesn't think using ground troops to get in the middle of intense urban conflict and civil war is on the allies' minds right now.

Keeping the pressure on Gadhafi and letting his forces know that the coalition is well intact is the hope, even if the allies don't want to fight house to house themselves, Flanagan said.

At the same time, he said, "it's hard to speculate. If Misrata fell would there be a turn?"

Another analyst, the Brookings Institution's Michael E. O'Hanlon, questions the hesitance of "casualty-averse" Western democracies to provide aid such as military training. He thinks more aid might turn out to be bolder and more helpful than keeping the forces they are supporting with air power at arm's length.

He said the allies shouldn't content themselves with "incrementalism."

"We may wind up providing some of the things we're skittish about," he said.

Meanwhile, Italian Foreign Minister Franco Frattini said Tuesday that the international Libya Contact Group, charged with helping map out Libya's future, will discuss ways Libyan rebels can facilitate the sale of oil from rebel-held areas to international outlets when the contact group meets in Rome next month.

Transitional National Council President Mustafa Abdul Jalil, speaking with Frattini, reminded the world again of Gadhafi's indiscriminate attacks in population centers.

Aid groups have been attempting to pluck desperate people from Misrata, which is hemmed in by Gadhafi's forces on three sides. The only escape route is by sea. The International Organization of Migration chartered boats to evacuate stranded migrant workers and Britain said it will help another 5,000 people get out.

Mohammed, an opposition spokesman who wanted to be identified only by his first name for safety reasons, said Misrata residents are disappointed with NATO, empowered by the United Nations to use force to protect civilians. But Misrata had not seen NATO airstrikes in several days, Mohammed said.

"Gadhafi's forces are not threatened by NATO anymore. The NATO planes are circulating as the destruction continues," he said.

NATO, however, reported progress in its mission. As of Monday, it had flown 771 sorties and 1,110 strike sorties.

The NATO operation destroyed seven ammunition bunkers in the Tripoli area and four air defense radars in the Misrata area this week, the alliance said, along with equipment in the areas of Zintan and Sirte, Gadhafi's hometown.

NATO has said Gadhafi's forces have started hiding resources in civilian areas, making airstrikes more difficult to carry out without harming civilians.

But Gadhafi's regime has given no sign of standing down.

Valerie Amos, U.N. under-secretary-general for humanitarian affairs and emergency relief coordinator, met with the Libyan regime over the weekend.

"Let me be absolutely clear. I got no guarantees with respect to my call for the overall cessation of hostilities to enable people to move, to enable us to deliver supplies," Amos said Monday. "I did get an assurance from the government to carry out a needs assessment in Misrata."

She added, "I have to say, in that instance, we got no guarantees at all that the violence would cease."

CNN's Reza Sayah, Yousuf Basil, Ben Wedeman and Joe Sterling contributed to this report.