JACKSONVILLE, Ark. (AP) _ No signs of foul play were evident in the deaths of one adult and four children whose bodies were found Thursday at a duplex in central Arkansas, the town’s fire chief said.

Jacksonville Chief Bob Thornton said firefighters were called to the Max Howell duplex around 6 a.m. Thursday by a neighbor who reported smelling smoke. No one answered the door and firefighters using thermal imaging did not detect any signs of a fire from outside the apartment, Thornton said. The firefighters left without entering the apartment, he said.

A maintenance worker opened the apartment door and discovered the bodies an hour later, Thornton said.

The cause of death was not yet clear and there were no signs of foul play, he said.

There was no fire burning when firefighters returned to the duplex, but that there were signs that one had burned overnight, the chief said.

Multiple law enforcement agencies, including the state fire marshal and Arkansas State Police, were investigating.

Jacksonville is about 20 miles northeast of Little Rock and is home to the Little Rock Air Force Base, a training base for C-130 aircraft.

The fire chief said he didn’t know whether the victims were members of the military. He said the duplex was part of a low-income housing complex.