A $5,000 reward is being offered by the federal Bureau of Alcohol, Tobacco and Firearms for information that helps police find who was responsible for an early Sunday house bombing that injured a rural Lawrence couple.

Evidence of an explosive device was found at the damaged home of Lloyd and Karen Haas, 1808 N. 1100 Road, Douglas County Sheriff Rick Trapp said. The explosion occurred about 3:30 a.m. Sunday.

ATF is assisting the sheriff’s office in the investigation.

Karen Haas, 51, was taken to Lawrence Memorial Hospital, where she was treated and released. Lloyd Haas, 69, was taken to a Kansas City area hospital were he was listed in critical condition Monday night, a hospital spokesman said.

Sheriff’s officials Monday were saying little about the case. Larry Scott, spokesman for the ATF office in Kansas City, Mo., would only say that an investigation is continuing. Investigators would not say whether there are any suspects.

A front window of the home was boarded up Monday. But investigators refused to comment about the extent of damage done or what type of bomb might have been used.

The Haases could not be reached for comment.

In addition to ATF’s reward offer, Douglas County Crime Stoppers is offering a reward of as much as $1,000 for information leading to an arrest and conviction in the case.

Anyone with information can call the sheriff’s office at (785) 841-0007 or Crime Stoppers at (785) 843-TIPS (8477). Callers to Crime Stoppers remain anonymous.