A Vietnamese man died after falling from the eighth floor of a building in central Thailand on Monday morning.

The body of Tran Huu Dan, 24, was found on the road alongside the Chalerm Phrakiat building of Sukhothai Thammathirat Open University in Nonthaburi Province, Bangkok Post reported.

Local police are still investigating whether the death was an accident, suicide or murder.

Initial investigations shows Dan arrived in Thailand with other Vietnamese nationals to attend the World Vegetarian Meeting between May 22 and 30.

Dan and three other Vietnamese vegetarians were staying in a room on the eighth floor of the building.

According to the Bangkok Post, investigators said they found no evidence of a fight or assault in the room. All Dan’s belongings, including his passport, were still in the room.

A chair was found near the room’s window, from which Dan was believed to have fallen.

The three roommates have been summoned for questioning.