FREMONT -- Police shot and killed a dog they say lunged at officers, charged firefighters and bit an elderly man and his grandson outside a home in the Niles neighborhood.

Officers were dispatched to a home on Blaisdell Way about 5 p.m. Saturday after a homeowner dialed 911 to report a gray and white pit bull had attacked two people, according to police spokeswoman Geneva Bosques.

During the incident, the dog bit a man on his hand as the man had his hand on his grandson's shoulder. The dog also bit the man's grandson on the foot.

While on the phone with dispatch, the caller said that the dog was attacking "anything and everything in their yard" including a basketball, a tether ball and shoes. Residents, Bosques said, were locking themselves in their vehicles and homes for their safety.

The victims took cover in a neighbor's home, police said, but needed medical aid.

When an officer arrived, police said, the dog immediately charged him. The officer used his baton to keep a safe distance and attempted to get the dog into the back of the patrol car. But the dog took hold of the baton, ran off with it and destroyed it.

Fremont firefighters also arrived on scene unaware that the dog was still loose in the area. When they exited their truck to provide medical treatment to the victims the dog also charged them. Two firefighters scrambled into the truck cab, while the third was forced to climb up on top of the truck, Bosques said.

The pit bull then re-focused his efforts and charged the police officer, who then shot the dog one time. The dog died at the scene.

The dog had no tags and residents in the area said they had not seen the dog in their neighborhood before the attack.

The victims were transported to the hospital where they were treated for their injuries and released. Anyone with information about the dog is asked to call police at 510-790-6800 and select option 3.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.