( CNN ) -- Denver police opened a homicide case Wednesday after firefighters found five people dead inside a bar that was set ablaze . Police said they believe the bar was set on fire to mask the homicides inside . `` We 'd like to say this was an isolated incident , but I ca n't say that with any certainty , '' Denver Police Chief Robert White said Wednesday afternoon as he asked members of the public to help investigators . Police said they had received tips , but had no suspects yet . `` We 're asking if anyone has any information , no matter how trivial they think it is , please contact us , '' White told reporters . Reports of a fire at Fero 's Bar and Grill came in around 1:50 a.m. Wednesday . Firefighters working to put out the blaze found four women and one man dead , police said . `` Each victim 's body showed obvious signs of trauma indicating that a homicide investigation is warranted , '' police said in a written statement . Authorities did not identify the victims or release further details about their cause of death . Arson investigators were also looking into what caused the fire , police said . More from CNN Justice : . Bodies , secrets buried at school . Man arrested in plot to blow up NYC Federal Reserve . Police : 7 children lived in home strip club . CNN 's AnneClaire Stapleton and Shawn Nottingham contributed to this report .
NEW : Denver police ask the FBI for help in their investigation . It seems the house was set on fire to hide the bodies inside , investigators say . ` ` Each victim 's body showed obvious signs of trauma , '' police say . Four women and one man were killed .