BEIRUT (AP) — Activists say Syrian troops are shelling the central Houla area where more than 100 people were massacred last week.
The Britain-based Syrian Observatory for Human Rights and the Local Coordination Committees activist groups say Thursday's shelling of Houla was mostly by heavy machine guns.
Both groups also say a young man was killed by sniper fire in Houla, a collection of poor farming villages in central Homs province.
Survivors of the Houla massacre blamed pro-regime gunmen for at least some of the carnage that left 108 people dead, many of them children and women.
The Syrian government denied its troops were behind the killings and blamed "armed terrorists."
In the wake of the massacre, the United States, Western and Asian nations expelled Syrian diplomats in protest.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
BEIRUT (AP) — Thirteen bound corpses, many apparently shot execution-style, have been discovered in eastern Syria, U.N. observers said Wednesday, days after the massacre of more than 100 people provoked international outrage and the coordinated expulsion of Syrian diplomats from world capitals.
The latest killings happened in Deir el-Zour province, where the bodies were found late Tuesday blindfolded with their hands tied behind their backs. A statement by the U.N. mission said some appeared to have been shot in the head at close range.
A video posted online by activists showed the men lying face down, pools of dried blood under their heads.
The head of the U.N. observer team, Maj. Gen. Robert Mood, said he was "deeply disturbed by this appalling and inexcusable act."
The fresh killings underline violence that seems to be spiraling out of control as the uprising against President Bashar Assad that began in March 2011 has morphed into an armed insurgency. Activists say as many as 13,000 people have been killed since the revolt began.
In the wake of last weekend's massacre in Houla, in which nearly half of the 108 dead were children, the United States and Western nations expelled Syrian diplomats in protest — a move Syria's state-run media denounced Wednesday as "unprecedented hysteria."
The massacre drew continued harsh criticism Wednesday, even from Syria's closest ally Iran, with Iranian President Mahmoud Ahmadinejad saying that anyone responsible for the killings should be punished. "I'm not excluding anyone from this responsibility," Ahmadinejad told France 24 TV station.
U.N. investigators and survivors have blamed pro-regime gunmen for at least some of the carnage in Houla, a collection of poor farming villages in central Homs province, saying men in civilian clothes gunned down people in the streets and stabbed women and children in their homes. The Syrian government denied its troops were behind the killings and blamed "armed terrorists."
Damascus had said it would conclude its own investigation into the Houla deaths by Wednesday but it was not clear if the findings would be made public. The U.N.'s top human rights body planned to hold a special session Friday to address the massacre.
Meanwhile, violence continued unabated. Syrian forces bombarded rebel-held areas and clashed with army defectors in Homs province, killing at least eight people, activists said.
The United States, Britain, Canada, Australia, France, Germany, Italy, Spain and Bulgaria ordered top Syrian diplomats to leave on Tuesday.
On Wednesday, Turkey, Syria's neighbor and a former close ally, joined the coordinated diplomatic action, saying it ordered the Syrian charge d'affaires and other diplomats at the Syrian Embassy in Ankara to leave the country within 72 hours. The consulate in Istanbul will remain open for consular duties only.
Among the most outspoken critics of the Assad regime, Turkey closed its embassy in Damascus in March and withdrew the ambassador. Its consulate in Aleppo remains open,but the Foreign Ministry said it reduced the number of its personnel there on Wednesday.
Turkey's Prime Minister Recep Tayyip Erdogan also said new unspecified sanctions might be imposed against Syria in the coming days. The world "cannot remain silent in the face of such a situation," he said.
Japan also ordered the Syrian ambassador in Tokyo to leave the country because of concerns about violence against civilians. Japan's foreign minister, Koichiro Genba, said his country was not, however, breaking off diplomatic ties with Syria.
The Obama administration added new sanctions on a Syrian bank Wednesday as a top White House official said the U.S. wants to economically throttle Assad's regime and cut off salaries of pro-government thugs blamed for the grisly massacre in Houla.
The U.S. Treasury Department said the Syria International Islamic Bank has been acting as a front for other Syrian financial institutions seeking to circumvent sanctions. The new penalties will prohibit the bank from engaging in transactions in the U.S. and will freeze any assets under U.S. jurisdiction.
"We are strangling the regime economically," White House deputy national security adviser Denis McDonough said.
The international community has been grappling with ways to quell the deadly violence and spur a political transition. The U.S. and Western countries are loathe to use military intervention similar to last year's campaign in Libya to oust Moammar Gadhafi, fearing a backlash.
The White House said this week that such an assault risks leading to "greater chaos, greater carnage."
But for now, Syria can still count on the support of its allies China and Russia, which on Wednesday criticized the diplomatic moves.
"The banishment of Syrian ambassadors from the capitals of leading Western states seems to us to be a counterproductive step," Russian Foreign Ministry spokesman Alexander Lukashevich said. He said the move closes "important channels" to influence Syria.
U.N. special envoy Kofi Annan met with Assad on Tuesday in Damascus to try to salvage what was left of his peace plan, which since being brokered six weeks ago has failed to stop any of the violence on the ground.
Tensions have escalated as more information emerges about the May 25 killings in Houla.
The U.N.'s human rights office said most of the victims were shot execution-style at close range, with fewer than 20 people cut down by regime shelling.
The U.N. Security Council met behind closed doors Wednesday to hear briefings from Annan's deputy Jean-Marie Guehenno and U.N. peacekeeping chief Herve Ladsous.
U.S. Ambassador Susan Rice warned that a failure of Annan's peace plan could create a spreading conflict that creates "a major crisis" not only in Syria but also region-wide.
"And members of this council and members of the international community are left with the option only of considering whether they are prepared to take actions outside of the Annan plan and the authority of this council," she told reporters.
Associated Press writers Selcan Hacaoglu in Ankara, Turkey, Albert Aji in Damascus, Syria, and Edith M. Lederer at the United Nations contributed to this report.