More than 30 employees of one of the country's biggest automakers were taken to hospitals with injuries after a brawl broke out at the corporate New Year party in Chon Buri province.

AutoAlliance Thailand, the manufacturing joint venture between Ford and Mazda, held the celebration on Friday night for more than 4,000 of its workers at a restaurant in tambon Bo Win of Si Racha district.

Reportedly, the brawl started in front of the stage during the prize drawing event. The chaos quickly spread as glasses and other missiles were thrown with periodic explosions and gunshots also heard, according to some witnesses. A lot of property was also damaged or destroyed in the clash.

Police could not contain the situation at first because there were only 10 officers originally assigned to the party. The investigation team is currently questioning all those involved to determine who threw the first punch.

The police said that most of those injured were women hit by flying objects. Many of them were run over in a stampede as workers struggled to get away to safety. Backup emergency workers from surrounding districts had to be called in help shuttle the wounded to nearby hospitals.

One worker was in critical condition with a stomach would from an exploded homemade grenade.