Butler police say two unknown men tied up and robbed a mother and her adult son during a home invasion Tuesday night in Butler. The victims suffered minor injuries.

The 63-year-old mother and 37-year-old son were at their home on the 400 block of West Cunningham Street about 9:30 p.m. when they heard a knock on their door. Upon answering the door, police said, two men forced their way into the house.

The residents were forced into the basement where they were tied up, said Detective Lt. Chad Rensel. The son was tied up first, and the suspects then tied up the mother to him. Both victims' wrists were bound.

Police said the men then stole an unspecified amount of money from the house before fleeing.

The suspects, who did not display any weapons, were dressed in all dark clothing, including hooded sweatshirts. Their faces were covered with bandanas or masks and the hoods were pulled over their heads to hide their identities.

The victims also reported the men were wearing gloves.

Once the victims believed the suspects had gone, the son was able to untie himself and his mother, and he called 911, Rensel said.

Both victims had injuries to their wrists from being tied up. The son also had an injury to his head from being forced to the ground.

Rensel said police have obtained surveillance video, which is being reviewed, as part of their investigation.

Anyone with information about the incident is asked to call police. Questions may be directed to Rensel at 724-287-7743 , Ext. 213, or crensel@butlercitypd.com.