CHERRY HILL, N.J. (CBS) – Cherry Hill Police are looking for the suspects involved in a home invasion robbery that occurred while a brother and sister were still inside.

According to Cherry Hill Police, four male subjects ransacked a home early Tuesday afternoon after tying up the siblings.

The victims, both in their 20s, were at their home on the 1100 Block of Society Hill Boulevard when one of the suspects, dressed as a postal service employee, knocked on the door.

When the sister answered the door, the man forced his way into the apartment. Three additional males, two armed with handguns, followed inside and bound the sister and her brother, who is in a wheelchair.

“I just heard a loud boom from next door,” said neighbor Nurit Maor. “I wasn’t sure what was going on. I thought maybe the child fell or something because he lost his leg in an accident.”

The robbers, which include three Hispanic males and one black male, ransacked the apartment and fled with an undisclosed amount of cash and jewelry.

After about 15 minutes, the brother was able to free himself and his sister and call police.

Police say the family may have been targeted because they own a business, and the robbers may have been looking for money. The victims were not injured, according to police.

No arrests were made as of 5 p.m. Tuesday. Anyone with information is urged to contact the Cherry Hill Police Department Investigative Unit at 856-488-7833.