United Nations special envoy Kofi Annan arrived on Monday in Damascus to meet with Syrian President Bashar Assad on the heels of a weekend massacre that left more than 100 people—including what appeared to be "rows of bloody children"—dead.
The U.N. said at least 108 people were killed on Friday in the town of Houla—49 of them children. The Syrian government blamed rebel gunmen for the attacks, dismissing the suspicions of international watchdog groups and others that pro-regime forces were involved.
On Sunday, the U.N. Security Council condemned the killings "in the strongest possible terms" and called for an independent investigation.
"I have come to Syria at a critical moment in this crisis," Annan said in a statement upon his arrival. "I am personally shocked and horrified by the tragic incident in Houla two days ago, which took so many innocent lives, children, women and men. This was an appalling crime, and the [U.N.] Security Council has rightly condemned it."
Annan said those responsible "must be held accountable."
"I understand that the government is also investigating," he said.
Assad has come under intense scrutiny from world leaders in the wake of amateur video, released over the weekend, that showed "a room crammed with the mangled and bloody bodies of children—some with their skulls torn open," CNN said. According to the Associated Press, another video "showed the bodies, wrapped in white sheets, being placed in a sprawling mass grave."
"I intend to have serious and frank discussions with President Bashar al-Assad," Annan said. "Our goal is to stop this suffering."
More than 9,000 people have been killed since the uprising began in early 2011, according to U.N. estimates.
He added: "It must end, and it must end now. I urge the government to take bold steps to signal that it is serious in its intention to resolve this crisis peacefully, and for everyone involved to help create the right context for a credible political process. And this message of peace is not only for the government, but for everyone with a gun."
According to the Associated Press, Syrian troops killed 24 people early Monday in a shelling in Hama.