DARAA, Syria - A roadside blast hit troops escorting UN observers in Syria's south on Wednesday, a day after envoy Kofi Annan warned that his peace plan could be the last chance to avoid civil war.
The explosive device, apparently planted underground, wounded six Syrian soldiers escorting the convoy as it entered the city of Daraa, cradle of a 14-month uprising against President Bashar al-Assad's regime.
Major General Robert Mood, the head of the 70-strong UN mission, was in the four-vehicle convoy but escaped unharmed along with 11 other observers and his spokesman, Neeraj Singh, said an AFP photographer travelling with them.
The Norwegian general said the attack was "a graphic example of violence that the Syrian people" were suffering on a daily basis.
"It is imperative that violence in all its forms must stop," Mood was quoted as saying by Singh, who added: "We remain focused on our task."
The opposition Syrian National Council accused the regime of being behind the blast, the latest breach of a month-old ceasefire agreement brokered by UN-Arab League envoy Annan.
"We believe the regime is using these tactics to try to push the observers out amid popular demands to increase their numbers," SNC executive committee member Samir Nashar told AFP.
"(Anti-regime) demonstrators want the observers, because they provide a safety guarantee. In their presence, people can express themselves through peaceful protests," said Nashar.
"We are used to the regime's tactics of claims that there is terrorism and fundamentalism in Syria, which is not the case."
France strongly condemned the bombing.
"We hold the Damascus regime responsible for the observers' security," said foreign ministry spokesman Bernard Valero.
In other violence, troops pounded rebels hiding out in Douma near Damascus, said the Syrian Observatory for Human Rights.
In the village of Manshiya, near Daraa, several soldiers were killed and wounded when an explosion targeted their vehicle.
Clashes between regime forces and rebel groups killed one soldier in the village of Marata, northwestern Idlib province, said the watchdog.
Two security forces members were killed in eastern Deir Ezzor, the scene of heavy shooting and explosions, and a pro-regime gunman was killed in Aleppo, Syria's second city in the north.
One civilian was killed and three wounded in heavy machinegun fire by regime forces in Tell Ain al-Hamra, northwestern Idlib province, it said, adding a woman died in the central city of Hama from injuries suffered two days.
Security forces carried out arrest raids in Harasta, outside Damascus, and the villages of Al-Safira and Al-Hisan in Deir Ezzor province, the watchdog added.
In neighbouring Lebanon, cross-border gunfire from Syrian forces killed an elderly woman and wounded her daughter on Tuesday, an official said, a month after a Lebanese TV cameraman was killed in a similar shooting.
On Tuesday, Annan told the UN Security Council the priority in Syria was "to stop the killing," and expressed concern that torture, mass arrests and other human rights violations were intensifying.
Regime forces "continue to press against the population," despite a putative truce that started on April 12, but attacks are more discreet because of the presence of the UN military observers, diplomats quoted him as saying.
"The biggest priority, first of all we need to stop the killing," Annan told reporters in Geneva.
Annan briefed the council on his efforts to get Assad to implement the plan, which he said was possibly "the last chance to avoid civil war."
He stressed, however, that the peace bid was not an "open-ended" opportunity for Assad, diplomats who attended the briefing said.
Annan plans to visit Damascus for a second time in the coming weeks, his spokesman said, though this depended on events on the ground.
US ambassador to the UN Susan Rice said Washington's goal was still the removal of Assad.
"The United States remains focused on increasing the pressure on the Assad regime and on Assad himself to step down," Rice said.
Annan updated the UN body on the status of his six-point plan after UN chief Ban Ki-moon warned world powers were racing against time to prevent all-out civil war.
The current observers on the ground "have had a calming effect" and the deployment by the end of the month of a 300-strong team would see a "much greater impact," said the envoy.
Turkish Prime Minister Recep Tayyip Erdogan, meanwhile, urged the UN to bolster its mission to as many as 3,000 - well past the 300 authorised under a Security Council resolution.
The Observatory said Tuesday that almost 12,000 people, mostly civilians, have been killed in Syria since March 2011. About 800 of them had died since the truce was supposed to have taken effect.
The United Nations has accused both the government and rebels of violating the ceasefire.