Syrian government forces and rebel fighters exchanged gunfire in an upscale neighborhood in Damascus early Monday morning, local time, leaving three people dead.

The Wall Street Journal reports the gunfight broke out just several hours before the arrival of a UN delegation tasked with brokering a cease-fire, casting a shadow over the international community’s efforts to resolve the Syrian problem.

The two-hour-long gunbattle took place in Mezz, a tightly secured district of foreign embassies and residences for high-ranking Syrian government officials.

This is the first time Syrian government forces and rebel fighters have exchanged gunfire in central Damascus.