Syrian activists say violence across the country killed 17 people Friday.

The head of the Britain-based Syrian Observatory of Human Rights told VOA Friday that a blast in front of a police station in the northwestern city of Idlib killed two security forces and three civilians. Another explosion that shook a Damascus suburb killed two more security force members.

The Observatory said demonstrators protested after Friday prayers across Syria, including in Aleppo, Damascus and Dara'a. Two civilians died in that southern city, including 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.

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.

U.S. Secretary of State Hillary Clinton is discussing the Syria crisis Friday with United Nations-Arab League envoy Kofi Annan, who has warned the country likely will slide into all-out civil war if the situation does not change course.

The Clinton-Anna talks follow a report by the U.N. that its unarmed monitors were shot at and blocked from investigating 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.

Opposition activists say pro-government forces in Syria carried out Wednesday's massacre, which would be the fourth mass mass slaying of civilians in the past two weeks. The Syrian government blames unidentified “terrorists” for the violence.

Thousands of Syrians have died in attacks and clashes since the cease-fire was put in place, and the violence has continued despite the presence of hundreds of U.N. observers.

Mr. Annan's peace plan was brokered in April but has not been implemented. 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 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.