Four elderly North Carolina people found shot to death after an apparent home invasion were killed while they played cards, a sheriff said Tuesday.

News outlets quoted Halifax County Sheriff Wes Tripp as saying the two married couples had been sitting around a kitchen table when they were killed sometime between Sunday and Monday morning.

Tripp identified the four as 72-year-old Janice Harris and 88-year-old James Harris, who owned the home, and 76-year-old James Whitley and 67-year-old Peggy Whitley, both of whom were visiting the house.

Tripp said a family member found the bodies after checking on the home in the Glenview community, just off Interstate 95 north of Rocky Mount.

The sheriff said there were no signs of a struggle. He told a news conference that there were signs of forced entry and items of value missing from the home.

"It's very disturbing," Tripp said.

Authorities are still investigating the deaths and have made no arrests in the case. On his Facebook page, Tripp announced that his office is offering a $7,000 reward for information leading to the arrests of those responsible for the shootings.

Sheriff's offices from four counties have joined the investigation, as well as the N.C. Highway Patrol, the N.C. State Bureau of Investigation and the Enfield Police Department.

"We have a quadruple murder," Tripp said. "We want to use all available resources on this."