Syrian forces opened fire across two tense borders Monday, killing a TV journalist in Lebanon and wounding at least six people in a refugee camp in Turkey on the eve of a deadline for a cease-fire plan that seems all but certain to fail.
A witness at the Turkish camp said he saw two refugees killed, although that account could not be independently confirmed.
Across Syria, activists reported particularly heavy violence with more than 125 people killed in the past two days.
The Obama administration expressed outrage at the violence spilling over the borders, saying the Syrian government appeared to have little commitment to the peace plan that was negotiated by former U.N. chief Kofi Annan.
The latest bloodshed was a sign of how easily Syria's neighbors could be drawn into a regional conflagration as President Bashar Assad's crackdown on a year-old uprising becomes increasingly militarized, despite desperate diplomatic efforts to stop the violence.
Annan brokered a deal that was supposed to begin with Syria pulling its troops out of population centers by this morning, with a full cease-fire by both sides within 48 hours. But hopes for the plan collapsed after a fresh wave of violence and new demands by the regime for written guarantees that the opposition will lay down arms first.
The U.N. estimates about 9,000 people have been killed in Syria since March 2011, when the uprising began with mostly peaceful protests against Assad. But a government crackdown led many Syrians to take up weapons, transforming the conflict into an insurgency.
Monday, Syrian forces fired across the border into a refugee camp in Turkey, wounding four Syrians and two Turks, authorities said.
The soldiers were believed to be firing at rebels who tried to escape to the refugee camp after ambushing a Syrian military checkpoint, killing six soldiers, according to the Britain-based activist group Syrian Observatory for Human Rights.
Syrian troops fired about 40 rounds across the border into northern Lebanon, killing a cameraman for Lebanon's Al Jadeed television station, the station said. The camera crew was in Lebanese territory.
Ali Shaaban, who was born in 1980, was shot through the chest as he sat in a car; he died on the way to the hospital, Lebanese security officials said.
"If you see the car, you would think it was in a war zone," Shaaban's colleague, Hussein Khreis, told the station. "It is completely destroyed from the bullets."
The station said on its website that its staff "crawled for around two hours, during which we were under constant fire from the Syrian army."
"I ask forgiveness from Ali's family because I couldn't do anything for him," Khreis said in a broadcast on Al Jadeed, breaking into tears.
Shaaban is at least the ninth journalist killed while covering the conflict in Syria. Others include award-winning French TV reporter Gilles Jacquier, photographer Remi Ochlik and Britain's Sunday Times correspondent Marie Colvin.
Annan, an envoy to Syria for the U.N. and the Arab League, has tried to broker a cease-fire that would pave the way for talks to end the crisis. But the Assad regime introduced a new, last-minute demand Sunday, saying it cannot withdraw its troops without written guarantees from opposition fighters that they will lay down their arms.
Syria's main rebel group, the Free Syrian Army, rejected the demand for a written guarantee but said it will abide by its promise under Annan's plan to stop fighting -- as long as the regime does, too.