HARRIS COUNTY, Texas – Two men were killed Sunday in an apparent murder-suicide in Harris County.

Crime tape blocked off the 18300 block of Carriage Lane in the City of Nassau Bay.

A neighbor called 911 around 4:45 p.m. Sunday, after hearing arguing and later gunshots, according to police.

"We heard screaming, then five gunshots go off. So, our dad called the police," next door neighbor Katie Chambers said.

Nassau Bay Police said officers discovered two bodies in the living room of a home on Carriage Lane. Both appear to have died from gunshot wounds.

Investigators told KPRC2 they didn't know what may have led to the shooting.

"What was the cause for this to happen? what led to this?" asked Sgt. Glen Sharp, of the Nassau Bay Police Department.

Police said no one else was home at the time of the shooting, but a woman who lives there did return home.

On Sunday night, police said she was speaking with investigators.

Names and ages of the victims were not released as of Sunday evening, but neighbors told KPRC2 they were unaware of any prior incidents at the address.

"Totally surprising to me," neighbor Ed McKenzie said. "Nice family, never saw any evidence of any trouble."

"We'd see them and they said hi. They were perfectly fine, it seemed," Chambers said.

Investigators believe an assault rifle was used, but would not specify how many shell casings were found.

Stay with KPRC2 and click2houston.com for updates to this developing story.