Updated

A U.N. delegation tasked with investigating chemical weapons allegations in Syria has arrived in Damascus on the first such trip.

Swedish chemical weapons expert Ake Sellstrom and U.N. disarmament chief Angela Kane arrived Wednesday from neighboring Lebanon.

The Syrian government has invited them to visit Damascus for talks on the terms of a possible U.N. investigation.

The Syrian regime and the rebels fighting to topple President Bashar Assad accuse each other of using chemical agents in a March 19 incident in the village of Khan al-Assal on the edge of the northern city of Aleppo.

The government has asked the U.N. to investigate the Khan al-Assal incident, but refused to have a possible inquiry include other alleged chemical attack sites in the central city of Homs, Damascus and elsewhere.