OTTAWA -- Ottawa police have set up a tip line after more dead cats were discovered showing signs of human abuse.

Police are now looking into the deaths of six cats in the west end, an area bound by Greenbank, Baseline, Merivale and Hunt Club roads."

On Tuesday, police said four cats had been found dead. They have since found two more. 

Police say the investigations include ruling out the possibility that the cats were killed by other animals.

"Police are taking this investigation very seriously," police said in a news release. "Patrols have been increased and forensic officers have documented the deaths."

Anyone with information is asked to call the new tip line: 613-236-1222 ext. 5760. Anonymous tips can also be submitted to CrimeStoppers.

The Ottawa Humane Society has offered a $5,000 reward for information leading to an arrest.

On Friday, the Ottawa Humane Society urged owners to keep cats indoors while police investigate the deaths of six cats.

"This is an extremely disturbing pattern of violence," said Bruce Roney, OHS President & CEO. "The sooner the killer is in custody, the better."