Syrian troops killed 28 civilians in the central city of Hama on Monday, monitors said, as UN military observers toured protest centres near the capital and both the European Union and the United States imposed new sanctions.
The persistent bloodshed 11 days into a promised ceasefire sparked growing criticism from opposition activists of the fledgling UN mission which still numbers just eight observers out of a planned initial deployment of 30.
Government troops strafed Hama's Arbaeen neighbourhood and its environs with light and heavy machineguns, the Syrian Observatory for Human Rights said.
Video footage posted online by activists showed mortar rounds hitting the area with plumes of smoke rising skywards.
The UN observers visited several rebel suburbs near the capital and were met by thousands of protesters demanding the collapse of the regime.
Amateur video posted by activists on YouTube showed four of the unarmed observers in blue helmets walking in Douma, a northern suburb of Damascus, surrounded by a huge crowd waving Syria independence flags.
"The people demand the fall of the regime," some chanted while others called for the arming of the rebel Free Syrian Army.
Monitors also visited the town of Zabadani, 50 kilometres (30 miles) northwest of the capital, where regime forces and rebel fighters have clashed repeatedly in past months.
Fares Mohamed, an activist in Zabadani, said the observers' visit lasted barely a half hour.
"They refused to head to a location less than a kilometre (mile) from the town to see tanks hidden by the regime," said Mohamed, who was reached via Skype.
Two members of the observer advance team on Sunday set up base in the central city of Homs, scene of some of the fiercest fighting between government troops and rebels since the outbreak of the 13-month revolt against President Bashar al-Assad's regime.
The official state news agency SANA said the observers toured the battered city's Al-Waer neighbourhood on Monday.
UN leader Ban Ki-moon has decided that the deployment of 300 ceasefire monitors in Syria can start next week, a UN spokesman told AFP on Monday.
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Following a UN Security Council resolution that allowed the mission, Ban was left to make an "assessment" as to whether it was safe for the monitors to go. "The decision has been taken" and the monitors should start arriving next week deputy UN spokesman Eduardo del Buey said.
Activists have been sceptical of the UN mission, saying the regime was simply buying time and was not committed to the ceasefire plan.
Abu Omar, an activist in Damascus, said the observers were playing by the regime's rules by coordinating all their movements exclusively with the authorities.
"They are not coordinating with us and by not doing so, their mission does no good to the Syrian people," he told AFP. "Their mission is a failure because they are not working with people on the ground."
Despite a lull in the fighting in regions visited by the observers, the violence has continued unabated in other areas, activists say.
One civilian was killed overnight in Damascus province amid clashes between opposition and government forces, the Observatory said.
Five soldiers were also killed in clashes in Hama province and in Daraa province, south of Damascus, the watchdog added.
The United Nations has estimated that more than 9,000 people have died in Syria since the revolt against the regime of Bashar al-Assad broke out in March last year.
In a sign of Western frustration with Damascus, the European Union agreed Monday to slap new sanctions on the regime, banning luxury goods exports and further restricting the sale of items used to repress dissidents, a diplomat said.
The extent of the luxury ban has yet to be defined but the aim is to deliver a symbolic blow against the posh lifestyle of Assad and his glamorous British-born wife Asma, another diplomat said.
"The Assad couple, as well as his inner circle and leaders of the regime, must be made to understand that events in Syria will also impact their personal lives," the source added.
Brussels also decided to expand the blacklist of dual-use goods which can be used for internal repression or for the manufacturing of equipment used for internal repression.
US President Barack Obama ordered sanctions and visa bans for companies and individuals providing technological know-how, computers or other equipment that helps Syria and its main regional ally Iran oppress their people.
Obama said in an executive order that the two nations had committed serious human rights abuses through network disruption and by using tracking technology and by perpetrating the "malign use of technology."
The move blocks the property and interests of people who have participated in such trade and suspends their right of entry to the United States.