(CNN) -- A man lost both of his hands and four other people were injured in an explosion Friday morning at a southern Boston apartment building, Boston police said.
Police spokeswoman Neva Coakley said the nature of the explosion at the building in the Hyde Park neighborhood wasn't immediately clear. However, Boston Police Commissioner Edward Davis told The Boston Globe that the man who lost his hands had been mixing chemicals in his basement apartment, and that the chemicals exploded.
Two people, including the man who lost his hands, were taken to a hospital, and three others were treated at the site in the Hyde Park neighborhood for unspecified injuries, Boston police said.
Davis said the man mixing the chemicals might have been experimenting with fireworks, and investigators didn't immediately know why the chemicals exploded, according to the Globe.
The incident had "no connection to terrorism," Davis told CNN affiliate WCVB.
"He told us he was experimenting," Davis said, according to the station.
Firefighters were called to the four-story apartment building at 15 Riley Road shortly after 9 a.m. They quickly put out a fire in the basement, fire department spokesman Steve MacDonald said.
A caller reported hearing bangs and seeing smoke coming from the building, WCVB reported, citing police.
MacDonald said Friday morning that investigators were checking out potentially hazardous chemicals at the scene. But the site, which had been cordoned off during the initial probe, was deemed safe by Friday afternoon, Coakley said.