A French fighter jet reported attacking and destroying a Libyan plane near the coastal city of Misurata Thursday, as international forces continued attacks on Libyan targets and state television showed footage of people killed in Western air strikes.

The French Rafale fighter helping enforce a no-fly zone over Libya destroyed what was identified as a Libyan G-2/Galeb, which is a trainer aircraft, the Associated Press reported. A U.S. official told the wire service the Libyan plane may have been landing at the time of the attack.

The official, who cautioned that details were still being confirmed, provided information about the attack on condition of anonymity, because the incident had not been publicly announced by the French government.

Western airstrikes hit numerous targets in Libya overnight, and NATO ships patrolled the coast to block the arrival of weapons or new fighters loyal to Libyan leader Moammar Gaddafi.

At the same time, international aid organizations scrambled to address a potential humanitarian crisis in Misurata, a key city 130 miles east of Tripoli that has been besieged by government forces.

Airstrikes by Western allies on Wednesday seemed to bring a temporary respite from the fighting that had raged for six days in the city. But after nightfall, government tanks returned to the city center and resumed their attacks, according to a doctor at the city’s main hospital. “They are shelling everywhere,” he said by telephone.

Patients were being treated on the floor, medical supplies were falling short, fuel for the generator was running low, and water had been cut off, said the doctor, who spoke on the condition of anonymity because he feared retaliation by Libyan forces.

Humanitarian agencies and the U.S. government have been stockpiling supplies in eastern Libya and in nearby countries in case of emergency. “I am now worried about a humanitarian crisis in Misurata,” said Mark Ward, a top official with the U.S. Agency for International Development.

Libyan state television showed blackened and mangled bodies that it said were victims of airstrikes in Tripoli, AP reported. But the identity of the corpses could not be independently confirmed.

The Obama administration continued trying to shore up domestic backing for its role in the operation and to counter criticisms that the president had been either too cautious or too aggressive.

In a call with reporters, Democratic Sens. Carl Levin (Mich.), Jack Reed (R.I.) and Richard J. Durbin (Ill.) predicted strong bipartisan support for the U.S. role when Congress reconvenes next week. Durbin said that President Obama had chosen a “very wise course, reminiscent of President George H. W. Bush . . . who built international cooperation” before initiating military action against Iraqi forces in Kuwait in 1991.

But House Speaker John A. Boehner (R-Ohio) sent a letter to Obama on Wednesday saying that he and other lawmakers were troubled that “U.S. military resources were committed to war without clearly defining for the American people, the Congress, and our troops what the mission in Libya is and what America’s role is in achieving that mission.”

Complex environment

The allied air attacks since Saturday have been credited with keeping Gaddafi’s forces from overrunning Benghazi and potentially carrying out a bloodbath in Libya’s second largest city. But they have deepened the stalemate elsewhere in the country.

U.S. and allied warplanes on Wednesday aimed their attacks on Gaddafi’s ground forces in Misurata and other key cities but were constrained by fears that strikes in heavily built-up areas could cause civilian deaths.

“It’s an extremely complex and difficult environment,” said U.S. Navy Rear Adm. Gerard Hueber, the chief of staff for the coalition.

U.S. military officials have repeatedly called on Gaddafi’s forces to pull back from populated areas so that food, water and fuel can flow in. “Humanitarian assistance must be allowed to reach the people of Libya,” Hueber said.

International aid organizations have been unable to deliver relief goods to Misurata and other contested towns. Asked whether the U.S. military might play a role in distributing emergency relief, one American official said, “All options are on the table.” He declined to comment further.

In recent days, the World Food Program and International Committee of the Red Cross have moved nearly 2,000 tons of food and other relief supplies into parts of eastern Libya that are under the control of rebel forces. The U.S. government has paid for some of that food and has provided nongovernmental groups in Libya with medical supplies sufficient to treat 40,000 people, officials said.

Abeer Etefa, a spokeswoman with the World Food Program, said the group was planning emergency operations to feed 600,000 Libyans in the next three months.

She said access to food “is becoming increasingly difficult” because of store closures in contested areas. Her agency said this week that in some areas, the price of flour had doubled, the cost of rice had risen 88 percent and the price of vegetable oil had jumped 58 percent.

“If the situation continues like that, it will be very worrisome, simply because this is a country that depends on food imports,” said Etefa, speaking from the Libyan-Egyptian border.

Aid agencies are able to bring supplies into eastern Libya by truck from Egypt or through the rebel-controlled port of Benghazi. But the Libyan government has not allowed aid workers to move freely in areas it controls, making it difficult to assess the extent of the crisis, officials said.

An Obama administration official said there were unconfirmed reports of about 80,000 people displaced inside Libya. “That number is likely higher,” said the official, who was not authorized to comment on the record.

In Brussels, NATO ambassadors continued to discuss a plan for the United States to relinquish command of the Libya mission to a broader coalition. The plan, agreed to by President Obama and his British and French counterparts, would turn military control of the operation over to NATO, with operational headquarters at the Naples-based Allied Joint Forces Command.

Political decision-making and oversight would be supplied by a larger group of partners, most likely made up of NATO’s North Atlantic Council and representatives from non-NATO countries participating in the military mission, including Arab states. U.S. and European officials said they hoped for agreement on the plan by the end of the week.

Meanwhile, Britain said it would host an international conference in London on Tuesday for all countries involved in the Libya situation, including those not contributing military assets. In addition to discussing implementation of United Nations resolutions on Libya, Foreign Secretary William Hague said the gathering would “consider the humanitarian needs of the Libyan people and identify ways to support the people of Libya in their aspirations for a better future.”

Sly reported from Tripoli, Libya. Staff writers Felicia Sonmez, Greg Jaffe and Karen DeYoung in Washington contributed to this report.