Several police officers were injured in a large explosion Wednesday evening during a standoff with a barricaded suspect in North Haven, Conn., officials said.

The explosion, in the 300 block of Quinnipiac Avenue, was so powerful that residents up to a mile away said their homes shook. The property where it happened burst into flames, filling the neighborhood with smoke and burning well into the night.

Yale New Haven Hospital confirmed on Twitter that it had received nine patients, up from an initial report of seven. The North Haven Police Department said that all nine were members of a SWAT team. As of Thursday afternoon, four had been released from the hospital and five were still being treated for “trauma-related” injuries, the department said.

The town’s first selectman, Michael J. Freda, and its third selectman, Sally J. Buemi, said Wednesday that the injuries were not life-threatening.