A handful of UN observers toured Syria on Wednesday as another 17 people died and France said the UN-backed peace plan was "seriously compromised."
UN-Arab League envoy Koffi Annan had urged a rapid deployment of the full, 300-strong observer team agreed by the UN Security Council, and French Foreign Minister Alain Juppe said they should be on the ground in a fortnight, not three months.
At least 14 civilians were killed across the country, including in cities visited by monitors, taking to nearly 300 the number of people who have died since a tenuous ceasefire went into effect on April 12, the Syrian Observatory for Human Rights said.
Among them were four people whose bus was raked with gunfire by security forces at a checkpoint near Khan Sheikhun, a town in the restive northwestern province of Idlib.
The Britain-based watchdog said two civilians were also killed by regime forces in the Harasta suburb of Damascus.
Another two civilians, including a teenage girl, were killed by sniper fire in Douma, a northeastern suburb of the capital, where regime forces conducted raids, searching for people wanted by the authorities.
It was unclear whether UN monitors, who visited Douma on Wednesday, were present before or after the shootings and raids took place.
Three soldiers died in clashes with armed rebel groups in the southern province of Daraa, cradle of the uprising against President Bashar al-Assad, where two civilians also died.
And a child was shot dead in a village in the eastern province of Deir Ezzor, according to the Observatory.
Regime forces also reportedly killed one citizen in the town of Rastan, in the flashpoint central province of Homs.
Annan has branded the bloodshed "unacceptable" as he and world powers called for the speedy deployment of the 300 observers.
Given the ongoing violence, he said it was urgent for the 300 monitors to arrive in Syria quickly.
"We need eyes and ears on the ground, able to move freely and quickly, and to engage all parties -- something which must be guaranteed by the Syrian authorities," he said.
But UN peacekeeping chief Herve Ladsous said it would take at least one month to get the first 100 into Syria.
He told the Security Council Damascus was refusing to accept monitors from the Western and Arab coalition of countries in the so-called Friends of Syria group that has backed the Syrian opposition.
Addressing the UN Security Council via teleconference, Annan said he was "concerned" about the violence surging after observers visit individual cities.
The former UN chief said Assad has still not fulfilled a promise to end violence and said the situation was "bleak" and "unacceptable."
Annan said he was "particularly alarmed" at reports that government forces had entered the city of Hama after a visit by UN monitors and killed "a significant" number of people.
"If confirmed this is totally unacceptable and reprehensible," he told the council.
French Foreign Minister Alain Juppe said "things are not going well; the Annan plan is strongly compromised but there is still a chance for this mediation, on the condition of the rapid deployment of the 300 monitors."
The Damascus-based Syrian League for Human Rights said nine activists were "summarily executed" by government forces in Hama on Monday, a day after they met UN observers in the central city.
More than 30 people were also killed in a government assault on Hama's Arbaeen neighbourhood on Monday, monitors have said, prompting anger and criticism by activists who questioned the use of the UN observer mission given the unending bloodshed.
Neeraj Singh, spokesman for an advance team of UN monitors, which began arriving in the country on April 15 and currently numbers 15, said there were two observers based in Hama and two others in Homs, cities that have both witnessed fierce fighting between government forces and rebel troops.
The rest of the team is based in Damascus.
Singh said the observers, who are set to number 30 in the coming days, reported back to Annan daily on what they witnessed.
Annan's spokesman Ahmad Fawzi acknowledged that the truce aimed at ending 13 months of violence that the United Nations says has killed more than 9,000 people remained "extremely fragile".
He said satellite imagery showed the regime had not fully withdrawn all of its heavy armour from population centres as required by the Annan plan.
Fawzi added that in areas visited by the observers, the guns were falling silent but credible reports indicated the violence resumes once they leave.© ANP/AFP