Updated

A U.N. diplomat says Britain and the United States have notified the United Nations of 10 different incidents of alleged chemical weapons use by the Syrian government.

The diplomat, speaking on condition of anonymity because all the incidents have not been made public, said Wednesday that the Americans and British have found no evidence that the opposition possesses or has used chemical weapons.

Syria has refused to allow a U.N. investigation team led by Swedish chemical weapons expert Ake Sellstrom into the country to investigate allegations raised initially by Britain and France and then by the U.S.

Sellstrom was in Turkey Sunday and Monday, reportedly talking to doctors who treated victims of chemical use, and is expected to produce an interim report on his findings, the diplomat said.