WRAPUP 5-In Syria, killing goes on despite Annan plan
* Annan plan calls for troop withdrawal by end of day
* Opposition, France say no sign of Syrian compliance
* Syria says Annan must guarantee rebels respect truce
BEIRUT, April 10 (Reuters) - Syrian troops killed 31 people on Tuesday, pursuing a fierce assault on President Bashar al-Assad's opponents instead of silencing their big guns and leaving towns as promised under a fraying international peace plan.
United Nations-Arab League envoy Kofi Annan said it was "a bit too early" to dismiss as a failure his attempt to halt 13 months of conflict and, in a letter to world powers in the U.N. Security Council, said Assad must make a "fundamental change of course" and adhere to a ceasefire due to begin on Thursday.
"The plan is still on the table," he told a news conference in Turkey after visiting Syrian refugee camps and before flying on to Iran, a key sponsor of the Assad family's 42-year rule.
The former U.N. chief's plan, which calls for Syrian troops to pull back by the end of the day on Tuesday, won backing from Assad's friends in Russia and China, as well as from Western, Arab and other nations struggling to find a way to deflect the Syrian leader from his bloody crackdown on a popular uprising.
Annan said he had information the Syrian military was withdrawing from some areas but moving to others not previously targeted. He appealed to all sides to stop violence and to set no conditions for a ceasefire due to start at dawn on Thursday.
"I had hoped that by now we would have been much further ahead along the road to the government of Syria honouring its commitments and all the parties beginning to take steps to end all violence," he said, reiterating Thursday's deadline. "We still have time between now and the 12th to stop the violence."
In a letter to the Security Council, obtained by Reuters, Annan wrote: "The Syrian leadership should now seize the opportunity to make a fundamental change of course.
"It is essential that the next 48 hours bring visible signs of immediate and indisputable change in the military posture of the government forces throughout the country," he said, adding that the opposition also should cease fighting in order to "give no excuse for the government to renege on its commitments".
Shelling of restive parts of Homs killed at least 26 people on Tuesday and five died in violence elsewhere, opposition groups said, but there was no sign of a military pullout, with tanks still in cities such as Homs and Hama.
Opposition activists say hundreds of Syrians have been killed since Assad accepted Annan's proposals on March 27.
Citing satellite images, a French foreign ministry spokesman endorsed that view and denounced a Syrian assurance that troops were, in fact, withdrawing as a "blatant lie".
The White House also saw no sign of a pullback: "Leaders of the Assad regime ... make a lot of promises," spokesman Jay Carney said. "Those promises overwhelmingly turn out to be empty."
Nor did rebels immediately stop shooting. The anti-Assad Syrian Observatory for Human Rights said insurgents killed six soldiers in attacks on checkpoints on an eastern desert road.
State media reported the funerals of 33 security personnel on Tuesday, bringing to 58 the number it has said have been killed in two days. Syrian government media curbs make it hard to assess conflicting reports from inside the country.
As the end-of-day deadline loomed for Damascus to implement a withdrawal, Syrian Foreign Minister Walid al-Moualem demanded guarantees from Annan that rebels would also honour any truce.
"We will not ask the terrorist groups, which are killing, kidnapping and destroying infrastructure, for guarantees. We want Annan to give us these guarantees," Moualem said in Moscow.
The last-minute demand, a variant of one Syria made at the weekend, is not mentioned in Annan's proposals and looked designed to complicate his struggle to get all parties to comply with a six-point plan that is so far largely a dead letter.
The rebel Free Syrian Army will fight on if Assad fails to withdraw troops and tanks from in and around cities as required, a spokesman, Colonel Qassem Saad al-Deen, told Reuters.
The opposition Syrian National Council said Syrian forces were not complying and that world powers should impose an arms embargo among other measures if the peace plan failed.
"More time means more blood," Council spokeswoman Basma Kodmani told reporters in Geneva. "It is urgent to end the regime's repression and the regime itself."
China, which along with Russia has blocked punitive U.N. Security Council action against Syria, said it hoped all sides would immediately obey the U.N.-backed ceasefire, aimed at stopping the uprising from sliding into full-scale civil war.
Russian Foreign Minister Sergei Lavrov said he had told Moualem that Syria could be "more active, more decisive" in meeting the terms of Annan's plan, but he also urged foreign states to lean on opposition groups to stop shooting forthwith.
Moualem said some troops had already pulled back from cities in line with the peace plan, but he tied a full ceasefire to the entry of foreign monitors, another apparently new condition.
"An end of violence must be simultaneous with the arrival of the international observers," he said, adding that Syria wants a say in how the ceasefire monitoring team is composed.
The U.N. peacekeeping department sent an advance team to Damascus last week to discuss how to carry out Annan's plan for "an effective United Nations supervision mechanism".
An Arab League monitoring effort collapsed in January as intensifying violence made a mockery of an Arab ceasefire plan.
Assad's forces have killed more than 9,000 people in the past year, according to a U.N. estimate. Damascus says rebels have killed more than 2,500 soldiers and security personnel.
Lavrov asked Annan by telephone to step up efforts to ensure that the Syrian opposition adhere to his ceasefire plan, the Russian Foreign Ministry said.
It said Moualem had told Lavrov some government forces had withdrawn from Homs to their bases.
The violence has alarmed Syria's neighbours, especially Turkey which already hosts almost 25,000 Syrian refugees. At least five people, including two Turkish citizens, were wounded by cross-border fire into a refugee camp in Turkey on Monday.
Turkish Prime Minister Tayyip Erdogan accused Assad of personal responsibility for killing civilians and threatened an unspecified response to the cross-border shooting.
"He is continuing to kill 60, 70, 80, 100 every day," Erdogan said during a visit to Beijing. Assad's troops were "mercilessly" shooting fleeing women and children in the back.
NATO member Turkey has floated the option of carving out a "buffer zone" inside Syria to protect civilians, providing the U.N. Security Council authorised a move that could set up a confrontation between Assad's forces and the Turkish military.
Failure to end the violence would highlight the diplomatic stalemate pitting Assad's Western and Arab critics against his friends in Russia, China and Iran. They all call for calm but differ sharply on how to achieve this or on any political transition that could satisfy the antagonists in Syria.
Moscow and Beijing both mistrust what they see as a Western drive for U.N. intervention in member states on the basis of a "right to protect" civilians that was invoked for Libya last year, when NATO airpower helped topple Muammar Gaddafi.
Western powers say they will not meddle militarily in Syria, but will pile pressure on Assad if he fails to halt bloodshed.
France will host a meeting next week aimed at tightening sanctions on Syria and Britain proposed returning to the Security Council for a response if Annan's plan fails.
Foreign Secretary William Hague also said on Tuesday Britain would intensify support for the opposition and seek to get the Council to refer Syria to the International Criminal Court.