PHILADELPHIA (AP) - Police in Philadelphia are investigating after six people suffered fatal heroin overdoses in the city and several other users of the drug were hospitalized in addition.

Five of the six victims died within blocks of one another on Sunday in Kensington, a section of the city that has become synonymous with drug abuse.Police have been investigating a bad batch of heroin that's been circulating throughout the city for the past month or so. A specific brand has yet to be identified.A bad batch has been blamed for nearly 50 overdose deaths last month within the police department's East Division, which encompasses Kensington and parts of north Philadelphia.Police say a cluster of overdoses can occur when heroin is cut with toxic chemicals like fentanyl or rat poison.