Three Wichita, Kan., police officers who had been dispatched to check on a vacant house were injured on Saturday by “a possible explosion from an unknown device,” the police said.

The three officers were taken to a hospital — two with minor injuries and one in serious but stable condition, the Wichita Police Department said on Twitter.

The officers had been dispatched around 4 p.m. local time “to check a vacant residence” and were hurt after entering the house, the police said.

Chief Gordon Ramsay said the police had been called to the house by the owners, who had noticed that windows were open and were concerned that someone might have been inside. When the police arrived, they checked around the house and were given the key by the homeowner.

“They went inside, and almost immediately when they got into the threshold, there was some type of shot or shots or explosion,” Chief Ramsay told reporters.

“We don’t know if someone was inside, if this was a booby trap, we don’t know if it was a gun or if it was some type of improvised device,” he said. “That’s what we’re investigating right now.”

A bomb squad and a SWAT team were on the scene, according to the police, who asked people to avoid the area. The chief said residents in the immediate area had been evacuated.

A video posted on Twitter by Michael Stavola, a reporter for The Wichita Eagle, showed the police telling someone through a loudspeaker to come out unarmed and they would not be harmed.

“It is still an active situation,” the police said on Twitter. “We will provide updates as we learn new information.”

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives said that its agents were also on the scene, working with the state and local authorities to investigate.