At least 77 people were killed in Syria on Tuesday, activists said, with continued violence threatening the future of the United Nations observer mission overseeing a fragile peace plan, dpa reported.
"This is the highest death toll since the April 12 ceasefire went into effect, most of the casualties were from southern province of Daraa, central province of Homs and the northern province of Idlib," Syrian activist Omar Homsi told dpa.
Activists also reported late Tuesday that a car bomb explosion in the northern region of Aleppo inflicted material damage and wounded at least 20 people.
The surge in violence came as Syria celebrated its 66th anniversary of independence - and while UN Observers continued their negotiations with the Syrian regime to sign a protocol agreement to enable some 25 UN observers to arrive in Syria in the coming 48 hours, to monitor the shaky ceasefire, which was established last week.
Colonel Ahmed Himmiche, head of the advance UN team who arrived in Syria Sunday, said his team had made on Tuesday an "excellent" visit to Daraa, a Syrian province near the Syrian-Jordanian border.
"We can say that we are moving ahead ...," the Moroccan colonel said.
UN spokesman in Syria, Khaled al Masri, confirmed that the team visited Daraa and met with the governor Mohammed Khaled Al-Hannous late Tuesday.
Activists in the Daraa area told dpa that opposition protesters carried out a demonstration while the UN team were in the area, to denounce what they described as a "failed UN mission in Syria."
UN Secretary General, Ban Ki-Moon said Tuesday the mission has to be enhanced in numbers and backed by aircraft to ensure that a firm ceasefire takes hold throughout the country.
"There are many obstacles and the Syrian government is not helping to ease them off, which delays the movement of the team to prepare the ground for the larger batch of observers to arrive in Syria," a western diplomat based in Syria told dpa, on condition of anonymity.
Colonel Himmiche told reporters in Damascus earlier that the mission "is not easy and it will require coordination with all sides."
The UN Security Council has demanded full access for the team, but there are fears that the government will try to hinder the mission by forcing observers to travel with government minders.
The Arab League earlier this year pulled out an observer mission over escalating violence.
Under Annan's plan, Damascus was to withdraw its troops and heavy weapons from restive areas across Syria after a ceasefire and start a dialogue with the opposition.
French Foreign Minister Alain Juppe called for international sanctions against Syria to be strengthened, saying measures already in place were hitting the mark.
In Brussels, the European Union is preparing a fresh round of sanctions on Syria, its foreign policy chief, Susan Ahston said, warning the regime of President Bashar al-Assad that more than a lull in violence is needed to satisfy the international community.
Russia, Syria's main ally, criticized "foreign forces" as an obstacle to peace efforts in Syria and called for speeding up the deployment of the UN mission.
"There are countries and external forces that are not interested in the success of the current efforts by the UN Security Council, which have been trying to replace the (council) with various informal formats, such as groups of Syria's friends, persuading the opposition not to cooperate with the government in any matters, including measures to enforce a truce," Foreign Minister Sergei Lavrov said, according to the Itar-Tass news agency.
Meanwhile, the Dubai-based Al Arabiya television reported that the wives of the British and German ambassadors to the United Nations released a video Tuesday urging the wife of Syrian President Bashar al-Assad to demand that her husband stop the bloodshed in the country.
The video, which was released by Huberta von Voss-Wittig and Sheila Lyall Grant of Britain, asks viewers to sign an online petition to Asma al-Assad asking her "to take a risk and stand up for peace ... for the sake of the Syrian people."