A U.S.-based human rights group has reported that a "death squad" that targeted criminal suspects in a southern Philippine city allegedly was organized by the former mayor and was responsible for nearly 300 killings over the past seven years.

Human Rights Watch said Wednesday it has documented at least a dozen of the 298 killings from January 2007 to March 2013 based largely on accounts of former hit men, witnesses, relatives of victims and police officers in Tagum City.

Former Mayor Rey Uy has denied the allegations and says that they were based on testimonies coerced and paid for by drug dealers and illegal gamblers.

Human Rights Watch says President Benigno Aquino III has largely ignored the killings. There was no immediate comment from Aquino's office.