Updated

The U.N.'s top human rights body will hold a special session Friday on the deteriorating situation in Syria and last week's massacre of more than 100 Syrian villagers, officials said.

The U.N. Human Rights Council said Wednesday its special session will address the massacre in Houla, Syria, which drew international condemnation and prompted the U.S. and at least a dozen other nations to expel Syrian diplomats.

Council spokesman Rolando Gomez said the session will be called based on a request supported by 21 of the 47 nations that are council members. The request, he said, required support from at least a third of its members and was officially submitted by Qatar, Turkey, the United States, Saudi Arabia, Kuwait, Denmark and the European Union.

A total of 51 nations — including France, Germany, Britain, Bahrain, the United Arab Emirates and 25 others that have observer status on the council — signed their support for the session.

The Geneva-based council has met 18 times previously in special sessions since its creation in 2006, including three on Syria just last year in the wake of the Arab Spring revolutions. At the last of those sessions in December — the previous ones came in April and August — the council approved a resolution to criticize Syria's crackdown on opposition protesters and appointed a special investigator to probe abuses in the country.

That December resolution won the backing of 37 council members with support from the Arab League, the United States and European countries, but Russia, China and four other members voted against, with six abstentions. The Human Rights Council's actions are often used to lend moral weight to efforts at the U.N.'s most powerful body, the Security Council in New York, to demand a more binding international response.

The United States says it remains opposed to military action in Syria. The massacre has provoked strong global condemnation, but it is unlikely to trigger a military assault similar to last year's NATO-led campaign in Libya to oust its leader, Moammar Gadhafi.

A U.S. State Department spokesperson has said the United States will keep up pressure at the Security Council, where it holds one of five veto-wielding seats, to find ways to stop the violence by Syrian President Bashar Assad's forces.

As permanent Security Council members, Russia and China have used their veto power to block U.N. resolutions against Assad. The U.S., France and Britain hold the other permanent seats. But Russia, which has been especially crucial to Syria in providing a buffer from international action, has grown increasingly critical of Damascus in recent months, and the Houla massacre has prompted some of the strongest condemnations yet from Moscow.

The U.N. human rights office said Tuesday that most of the 108 victims in the town of Houla were shot at close range, including 49 children and 34 women, and entire families were gunned down in their homes.

Last week, a U.N. panel of independent human rights experts said the Syrian regime and an increasingly organized rebel force are carrying out illegal killings and torturing their opponents but found that government forces are still responsible for most of the violence in the uprising.

A cease-fire declared in April has been violated daily by both sides in the conflict as more than 250 U.N. observers based in cities around Syria scramble to monitor a peace plan brokered by international envoy Kofi Annan.

In Amman, Jordan, Annan held talks Wednesday with the Jordanian prime minister and foreign minister and later told reporters the world must "find a solution that will lead to a democratic transition in Syria and find a way of ending the killings as soon as possible."