The US warned Syria that the world was watching as its forces pounded opposition strongholds Saturday days before a UN-backed cease-fire was due to come into effect.
The bombardment, which Activists said killed more than 100 people, 87 of them civilians, was an apparent move to crush resistance before troops must withdraw, the Associated Press wrote.
The offensive has sent thousands of refugees surging into Turkey.
Almost half of those killed died in a Syrian army raid on the village of Latamneh, near Hama, the AP reported, adding that amateur video showed the body of a baby with bloodied clothes and an apparent bullet wound in the chest.
Others were members of the Free Syrian Army, a member of the so-called Syrian Revolution General Command told the Washington Post.
Shelling was also reported in Homs.
The U.S. ambassador to Syria, Robert Ford, who left the country for security reasons, issued a statement Friday saying that the US and the Friends of Syria group of nations were "closely monitoring whether these required actions [of the agreement] are occurring or not."
According to the Post, Ford posted satellite images on the embassy’s Facebook page that he said showed places where armored vehicles and artillery units remained poised to fire on civilians, including in Zabadani and Homs.
"The regime and the Syrian people should know that we are watching," the paper quoted Ford’s statement as saying. "The regime cannot hide the truth."
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Syrian President Bashar Assad last week accepted a cease-fire plan proposed by Kofi Annan, the joint UN-Arab League envoy to Syria, requiring troops to withdraw from towns by April 10 and provide more access for humanitarian groups.
The truce is also meant to pave the way for negotiations between the government and its opposition.
However, the AP wrote, Western leaders were skeptical about Assad's intentions because of broken promises of the past.
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Meanwhile, Turkish Prime Minister Tayyip Erdogan on Saturday expressed his government's fears that an all-out war in Syria would unleash a flood of refugees.
"At the moment we have 24,000 Syrians who have entered Turkey," Reuters quoted Erdogan as saying before departing on a trip to China.
"We are taking measures for this, though we will not close the gates. The United Nations, however, has to toughen its stance. In particular Kofi Annan has to hold firm. He announced a deadline of April 10. I believe that he should monitor the situation very closely."
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