A man hunt is underway in Philadelphia for an Iraq war veteran suspected of killing six family members.

Police have advised locals to lock their doors as they intensify the search for 35 year-old Bradley William Stone.

The former soldier is believed to have gone on a shooting spree, first killng his ex-wife’s sister, husband and 14-year-old daughter.

An hour later police were called to a different home where they found two dead women – Stone’s former mother-in-law and her mother.