A woman who is six months pregnant and her two young sons escaped injury when a fire broke out yesterday in their South Amboy home, officials said.

The family cat was saved using cardio-pulmonary resuscitation.

The fire struck the three-story South Pine Avenue house shortly after 5:30 p.m., city Fire Marshal Ed Szatkowski said.

The mother, whose name and age were not immediately available, was taken to a hospital to be checked out because she is pregnant, the fire marshal said.

Her children, an 11-year-old and his younger brother whose age was not available, were not injured, Szatkowski said. Neither child’s name was released.

The investigation into the fire is continuing, but officials said they suspect it may have been caused by an electrical problem.

Family members told authorities the older brother was called out of his room by his mother, and when he returned, the room was filled with smoke, the fire marshal said.

The mother tried to use a fire extinguisher to put out the blaze, but the equipment did not work. At that time, the family fled the apartment.

Two South Amboy firefighters rescued Oliver, the family’s calico cat, according to Szatkowski. Firefighter Michael Wilday performed CPR, and oxygen was administered. Wilday was assisted by firefighter Chris Norek.

It took some 70 firefighters about 30 minutes to put out the fire, Szatkowski added. The blaze gutted the second floor, and the first and third floors sustained extensive water and smoke damage.

No one besides the mother and her sons was in the house when the fire broke out, Szatkowski said. The family is staying with relatives.