BRUSSELS >> NATO warships started patrolling off Libya’s coast Wednesday to enforce the U.N. arms embargo, as the alliance appeared set to assume responsibility for the no-fly zone over the North African nation to protect civilians.

Canada’s Brig. General Pierre St. Amand said naval operation Unified Protector “is now under way” with six vessels involved during the first day of patrols. NATO had already received offers for up to 16 ships to patrol the Mediterranean off Libya, he said.

Turkey, NATO’s sole Muslim member, is an integral part of the naval blockade, having offered four frigates and one submarine, St. Amand said. Other nations offering vessels are the United States, Romania, Italy, Canada, Spain, Britain and Greece.

Separately, Turkey has been seen as holding up agreement on a command structure for a no-fly zone, but diplomats say an agreement is gradually emerging about the role NATO would play, after the United States — which has effectively commanded the operation until now — reiterated that it was committed to the transition.

The compromise proposal would see NATO take a key role in the military operation guided by a political committee of foreign ministers from the West and the Arab world. Officials said the North Atlantic Council — NATO’s top decision-making body, which already has approved military plans for enforcing the no-fly zone — may decide to start them later Wednesday.

“These are difficult discussions on very difficult issues,” Lungescu said. “What you are seeing now is all 28 allies discussing them in a very constructive spirit.”

Spanish Defense Minister Carme Chacon endorsed the proposal for handing over control of the Libya operation to a political committee. “We are comfortable with that,” she said.

Germany is in a more difficult situation. The government, which is refusing to participate in the no-fly operation, approved on Wednesday sending air crews to man NATO’s surveillance planes over Afghanistan after withdrawing troops from the alliance’s Mediterranean Sea missions to avoid involvement in Libya.

The government’s decision to send up to 300 troops to man AWACS surveillance planes over Afghanistan is intended to help ease the strain on other NATO members, who may need to deploy to the Mediterranean.

Military experts say coordinating the enforcement of a no-fly zone over a nation the size of Libya requires a specialized and experienced staff of several hundred people. The U.N. Security Council authorized the no-fly zone to protect Libyan civilians after leader Moammar Gadhafi launched attacks against anti-government protesters who wanted him to leave after 42 years in power.

The mission to provide round-the-clock coverage of Libyan airspace would require not just fighter planes patrolling the skies, but also attack jets armed with anti-radar missiles to suppress any threat from the ground. It would entail several aerial tankers flying circular patterns over the Mediterranean to refuel the warplanes. At least one and probably two AWACS airborne surveillance and control aircraft would also have to be nearby to monitor and coordinate the entire operation.

The United States is one of the few nations with the operational headquarters capable of controlling such a complex mission. None of NATO’s European members have that capability and therefore rely on the alliance to provide it.

“The best outcome would be to have NATO handle military coordination, but hand political decisions to an ad hoc council of states participating in the coalition, including Arab countries,” said Francois Heisbourg, director of the Foundation for Strategic Research, a think tank funded by France’s Defense Ministry.

If NATO assumes responsibility for the enforcing the no-fly zone over Libya and the U.N. arms embargo against Libya, this would be controlled from NATO’s operational center in Naples, a NATO official said, speaking on condition of anonymity due to restrictions on talking to the press.

The allies agreed Tuesday to organize the naval mission, which initially will consist of two NATO naval flotillas that routinely patrol the Mediterranean. They are made up of two frigates, six minesweepers and a supply ship. The NATO official said more nations are likely to contribute warships in coming days.

Alliance spokeswoman Oana Lungescu said the action was to “cut off the flow of arms and mercenaries. We have intelligence reports that this activity is continuing, so it is quite important that NATO take action to stop this,” she said.

The operation will be similar to a naval mission carried out by NATO ships in the Adriatic Sea during the 1992-1995 war in Bosnia that also enforced an arms embargo.

Meanwhile, Turkey’s president called on Gadhafi to step down as soon as possible, saying that would help stop the bloodshed. Abdullah Gul said Wednesday such a move would also “deny the opportunity to others to plunder” their country.

Turkey has been insisting on a narrow military mandate for a NATO role in the military operation in Libya and assurances that no occupation of Libya will ensue.

In Moscow, Russia’s parliament in a preliminary vote passed a measure calling on the U.N. to impose a cease-fire in Libya and stop the violence against civilians.

There are no reliable civilian death tolls from Libya. Rebels say over 1,000 people have been killed in a month of fighting, while Gadhafi claims the toll stands at 150.

In Oslo, Norway gave the go-ahead for six F-16 fighter jets to join the no-fly zone operation. The planes were transferred to an air base on Crete on Monday.

Defense Minister Greta Faremo said the Norwegian planes would be ready to join the operation in a few days.