Syrian activists say violence nationwide killed 17 people Friday as discussions continued on ways to end the crisis.
International envoy Kofi Annan called for additional pressure on the Syrian government even as he met with U.S. Secretary of State Hillary Clinton in Washington.
"Everyone is looking for a solution," said Annan. "Some say the plan may be dead. Is the problem the plan or the problem the implementation? If it's implementation, how do we get action on that?"
The cease-fire brokered by Mr. Annan has failed to deter attacks by the Syrian government and clashes with opposition rebels that have left hundreds dead.
Clinton said the pair will try to figure out how to "engender a greater response" by the Syrian government to Mr. Annan's overtures.
Meanwhile, the violence continued in Syria. The head of the Britain-based Syrian Observatory of Human Rights, Rami Abdelrahman told VOA Friday that a blast in front of a police station in the northwestern city of Idlib killed two security force members and three civilians. Another explosion that shook a Damascus suburb killed two more security force members.
The Observatory said demonstrators took to the streets after Friday prayers across Syria, including in Aleppo, Damascus and Dara'a. Two civilians died in that southern city. One shot by a sniper.
Government troops shelled Homs while heavy fighting left two killed in Latakia. The activist group also reported deaths in Deir Ezzor.
Also Friday, the Committee to Protect Journalists said five citizen journalists documenting the unrest in Syria were killed at the end of May.
In Geneva Friday, the International Committee of the Red Cross said the humanitarian situation in Syria is "extremely tense." An ICRC spokesman told reporters that Syrians are finding it more and more difficult to reach food and medicine.
The announcement came as the U.N. said its observers had reached the site of a recently reported massacre in central Hama province. Activists said at least 78 people, including women and children, were killed this week in the village of Mazraat al-Qubeir.
The U.N. observers had been trying to reach the site since Thursday, but the U.N. says gunmen shot at the unarmed monitors and blocked them from investigating.
Opposition activists say pro-government forces in Syria carried out Wednesday's massacre, which would be the fourth mass slaying of civilians in the past two weeks. The Syrian government blames unidentified "terrorists" for the violence.
Mr. Annan's peace plan was brokered in April but has not been implemented despite the presence of hundreds of U.N. observers. He warned Thursday against allowing "mass killings to become part of everyday reality in Syria."
The former U.N. secretary-general called on the divided U.N. Security Council and the rest of the international community to unite and act immediately to intensify pressure, especially on Syrian President Bashar al-Assad's government.
During a visit to Istanbul Thursday, Clinton said the Syrian leader has "doubled down on his brutality and duplicity," and that the time has come for a post-Assad Syria.
Related report by VOA's Meredith Buel. We caution viewers, you may find some images in this report disturbing: