Three men were injured after a small explosion in Spalding on Saturday.
Police received a report of the incident on Gedney Drove at 10.53am on October 17.
Three men were taken to hospital, including one with a serious injury which is not believed to be life threatening.
The other two men are thought to have less serious injuries.
Paramedics, an air ambulance and a bomb disposal unit also attended the scene, with the EOD team making sure the area was safe.
The incident has been referred to the Health and Safety Executive, who will carry out an investigation.
A HSE spokesperson said: “HSE is aware of the incident and liaising with the police.”