UN observers in Syria described an attack on a village in the Hama region - where about 220 people were reported killed - as "an extension" of a Syrian Arab Air Force (SAAF) operation, the UN mission said in an assessment obtained by Reuters on Friday.
"The situation in Hama province continues to be highly volatile and unpredictable," the so-called "flash report" from the UN observer mission said. "SAAF forces continue to target populated urban areas north of Hama City in a large scale."
Opposition sources said about 220 people, mostly civilians were killed in the village of Tremseh when it was bombarded by helicopter gunships and tanks then stormed by militiamen who slaughtered some families on Thursday.
"The operation in Tremseh is assessed as an extension of the SAAF operation in Khan Sheikhoun to Souran over the recent number of days," said the two-page report by the UN mission in Syria, known as UNSMIS.
There were no independent accounts of the number of dead or how they were killed. If scores of civilians were killed, this could be the worst atrocity in 16 months of fighting between rebels and the forces of President Bashar Assad.
According to the UNSMIS report, a patrol of unarmed UN military observers could only get within about 4 miles (6 kilometers) of Tremseh and were stopped from getting closer by SAAF commanders because of "military operations."
The patrol observed the situation from a few different locations around Tremseh for about eight hours during which time it heard more than 100 explosions, sporadic small arms and heavy machine gun fire and saw white and black smoke plumes.
It also saw an Mi-8 and two Mi-24 helicopters flying overhead and witnessed one of the Mi-24 helicopters firing air to ground rockets.
"The patrol received several calls from local contacts claiming 50 people had been killed and 150 wounded within Tremseh," the report said. "Attempts (by the patrol) to contact the local military commander during this period were unsuccessful."
Want to enjoy 'Zen' reading - with no ads and just the article? Subscribe todaySubscribe now