Police in the northeastern U.S. state of Pennsylvania say at least three people are dead after a gunman walked into a fitness center and opened fire Tuesday night.

The tragedy took place in Collier Township, located near Pittsburgh.  Investigators say the gunman walked into an exercise class and turned off the lights, then pulled at least one gun out of a bag and began shooting.

The shooting lasted for several seconds before the man turned the gun on himself and committed suicide.

At least seven other people were wounded, including five victims in critical condition with multiple gunshot wounds.

All the victims were women.  Police say they do not have a motive for the shootings.

Some information for this report was provided by AFP, AP and Reuters.