A PREGNANT York woman and three men were put at risk of serious injury when a powerful firework was thrown into a room where they were chatting.

The mother of the 21-year-old woman said she was 18 weeks pregnant with her first baby, and the shock of the firework going off at the tenanted property in Byland Avenue, Bell Farm, York, on Wednesday night could have sent her into premature labour.

“It’s terrible,” said the mother, who did not want to be identified. “I was absolutely devastated. She’s OK but could have lost the baby.”

A man who said he lived in the room said he was sitting at his computer chatting to the woman and two men when the firework, the size of a large onion, was thrown through a small open window but he did not think it went off fully.

North Yorkshire Police issued a stern warning about the potentially deadly dangers of firework misuse.

Detective Chief Inspector Heather Pearson, of York CID, said: “We cannot stress enough how dangerous this incident was and can only remind people of the tragic death of an 83-year-old Harrogate woman, who died in 2008 after youths placed a firework in a wheelie bin which spread to her home.”

A fire spokesman said the blaze, which caused smoke and fire damage in the room, was tackled by two York crews with a hose reel jet.

Police said two York men, aged 27 and 30, were arrested early today on suspicion of arson with intent to endanger life and were being questioned in custody. A spokeswoman said officers conducted searches of a property and discovered a large quantity of display fireworks, which had been seized along with a vehicle. She appealed for anyone in Byland Avenue around the time of the incident or with any other information to call 0845 60 60 247, quoting reference 12110182072.