An unidentified man set himself on fire early Sunday when police officers tried to subdue him after he hurled a bottle at the Chinese Consulate General in Osaka, police said.

The man suffered serious burns and was hospitalized. Police said he set fire to his clothing when he was questioned by two officers at around 2 a.m.

The fire spread quickly, and police suspect the man, who was wearing a down jacket, had spread some kind of oil on his clothes. The officers put out the fire with a fire extinguisher.

The man was not identified, but police said he appeared to be between 30 and 50 years old.

According to the police, the man was walking toward the consulate and suddenly threw a glass bottle at the entrance when he was stopped and questioned by police on duty nearby.

The Osaka Prefectural Police have stepped up security around the consulate and other Chinese government establishments in the Osaka area following waves of anti-Japan demonstrations in China over the past three weekends.

The consulate said it received on Friday an envelope containing a razor and a message protesting the demonstrations. The consulate also received a mailed package containing a bullet last Monday.