Police in Texas found the bodies of six members of a Bangladeshi family who died in an apparent murder-suicide carried out by two brothers, US media reported Tuesday.

The bodies were found Monday in a home in Allen, a suburb of Dallas, according to the reports.

The dead were the parents of the family, a grandparent, twins aged 19 and another brother, Sergeant Jon Felty, an Allen police spokesman, told media.

Allen police found the bodies after a friend of the family called police around 1 a.m. Monday and expressed concern that someone in it was suicidal, Felty said.

"The two brothers had entered into an agreement that they were going to complete suicide, and from that, it went to where the entire family was taken with them," he told NBC News.

Felty said one of the brothers left a detailed post on Instagram describing what happened.

Police believe the killings occurred Saturday and that one of the brothers recently bought a gun, the Dallas Morning News reported.

Neighbors described a loving family headed by parents who were proud of their children, part of a tight-knit Bangladeshi community.

"We have never had an incident like this in the 21 years that I have been here," Felty said. "It's just a tragedy. There's no other way to describe it. It's a tragedy that you just can't imagine."