A team of U.N. observers has arrived in the Syrian town of Houla, where activists say intense government shelling has killed at least 90 people since Friday, including 25 children.

The attacks could further strain a fragile six-week-old cease-fire between government and opposition forces.

The observers arrived in the region Saturday. Earlier, the Syrian Observatory for Human Rights told VOA the government raids had prompted residents to flee from their homes, and also prompted an anti-government protest in Damascus Saturday.

The French news agency says the opposition Syrian National Council has urged the U.N. Security Council to convene an emergency session Saturday to address the deadly violence.

On Friday, U.N. chief Ban Ki-moon said a “stepped-up security crackdown” by the Syrian government had led to “massive violations of human rights” by both sides of the conflict.

In a report to the Security Council, Mr. Ban said the presence of unarmed U.N. observers was having a calming effect but the overall level of violence in the country remained quite high.

The Syrian government has blamed what it calls “armed terrorist groups.” It said seven people were killed in the Hama region Friday after a terrorist group opened fire on mourners.

The violence has continued in spite of a peace plan brokered by international envoy Kofi Annan six weeks ago. A spokesman for the former U.N. secretary-general says Mr. Annan will travel to Syria soon for what would be his first visit since presenting the peace plan in March.

Syria's unrest is having an impact in northern Lebanon, where ethnic clashes between opponents and supporters of President Bashar al-Assad have left at least 11 people dead and over 100 wounded in recent days.

The U.N. says more than 10,000 people have been killed in Syria since the government began its crackdown on dissent over a year ago.

VOA's Scott Bobb reports from northern Lebanon that tensions there are still running high. “Historically, Syria has wielded a great deal of influence in Lebanon, its smaller neighbor, and even occupied it for years up until a few years ago. Although Syria did withdraw a few years ago, the influence is still there and it is resented by many people. In this particular case, in Tripoli, what happened was a Salafist sheikh, the Sunni Islamist, was killed at a checkpoint. He was known to be opposed to the regime of Bashar al-Assad in Syria, and this raised tensions with the local Allawite community, to which President Mr. Bashar al-Assad belongs.”