Syria's government is denying responsibility for the killing of more than 90 people in the central Syrian town of Houla -- including 32 children -- in violence that has sparked an international outcry.
Syrian Foreign Ministry spokesman Jihad al-Makdissi said in Damascus that "terrorists" were responsible for the killings on May 25-26. He said the Syrian government was setting up a "military and legislative committee" to investigate.
Meanwhile, despite international condemnation of the killings in Houla, Syria's Army continued to bombard opposition strongholds in several parts of the country.
Iraqi security forces were deployed along the Iraq-Syria border after clashes broke out between Syrian troops and opposition fighters nearby.
On May 25-26, UN monitors tried to enter Houla to confirm what was happening but were blocked by government forces.
Later, gruesome video images of the dead, including the children, were posted to social networking sites like YouTube and Facebook. The images triggered shock and disgust around the world, underlining the failure of a 6-week-old UN-backed cease-fire.
General Robert Mood, chief of the UN monitoring mission in Syria, said monitors later counted 92 bodies, including 32 children, in Houla.
"The death of 32 innocent children -- lots of women and men, but in particular the children -- that is an unacceptable attack on the future and on the aspirations of the Syrian people," Mood said. "Whomever started, whomever responded, whomever contributed to it."
A photo released by the Syrian opposition shows UN observers inspecting the bodies of the 92 victims, more than 30 of them young children. The UN called the deaths a "brutal breach" of international law.
UN Secretary-General Ban Ki-moon and UN-Arab League envoy Kofi Annan have called the killings a "brutal" breach of international law by Syrian President Bashar al-Assad's regime.
They also have called on Syria's Army to immediately stop using artillery, tanks, and other heavy weapons against the civilian population and for the government to halt all violence by military or milita forces loyal to the regime.
Annan was expected to arrive in Damascus on May 28 to discuss the killings and growing international criticism of Assad's regime.
In Washington, U.S. National Security Council spokeswoman Erin Pelton said the attack serves as a "vile testament to an illegitimate regime that responds to peaceful political protest with unspeakable and inhuman brutality."
U.S. Secretary of State Hillary Clinton said the killings were a "massacre" and an "atrocity." She said UN observers "confirmed that dozens of men, women, and children were killed and hundreds more wounded in a vicious assault that involved a regime artillery and tank barrage on a residential neighborhood."
She said those who carried out the "atrocity must be identified and held to account." She also said the United States would work with the international community to intensify pressure on Assad and "his cronies, whose rule by murder and fear must come to an end."
Opposition activists said forces loyal to Assad had shelled Houla after a large opposition protest and skirmishes pitting government troops against fighters from the Sunni Muslim-led insurgency.
They say Assad's Shabbiha militia -- which is loyal to an establishment dominated by members of Assad's minority Alawite sect -- stormed the Sunni-dominated area from Alawite villages nearby, gunning down men in the streets and stabbing women and children in their homes.
The Arab League on May 27 announced it would meet in emergency session on June 2 in Qatar's capital, Doha, to discuss the Houla killings.
Britain said it wants a "strong international response," while France said it would contact the Friends of Syria group to try to arrange a meeting.
Exiled leaders of Syria's political opposition, meanwhile, were meeting in Istanbul with Turkish Foreign Minister Ahmet Davutoglu.
With reporting by Reuters, AP, and AFP