EAGLEVILLE, Pa (REUTERS) - The body of an Iraq War veteran suspected of fatally shooting six family members in Pennsylvania was discovered on Tuesday following a two-day manhunt, a district attorney said.

Suspect Bradley William Stone, 35, of Pennsburg was being sought in the deaths on Monday of his ex-wife, her mother, grandmother, sister and two other family members, including his 14-year-old niece.

Montgomery County District Attorney Risa Vetri Ferman said she and other law enforcement officials would hold a briefing regarding the discovery of Stone's body on Tuesday afternoon.

The manhunt prompted lockdowns and cancellations of schools around Pennsburg, about 50 miles (80 km) northwest of Philadelphia, and residents had been advised to stay inside with their doors locked.

Stone's 17-year-old nephew was seriously wounded in the attacks and hospitalized in stable condition.

Stone's daughters, ages 8 and 5, were not harmed. He had taken them from his ex-wife's house and left them with a neighbour on Monday, Ferman said. His current wife and infant child also were safe.

The killings set off Pennsylvania's second recent high-profile manhunt after a seven-week chase to capture survivalist Eric Frein, 31, who accused of killing a state trooper in September.

Upper Perkiomen schools in the Pennsburg area were closed on Tuesday, the district said.

Stone suffered from post-traumatic stress disorder, the Bucks County Courier Times reported. He enlisted with the US Marine Corps Reserves in 2002, was deployed to Iraq and was honourably discharged at the rank of sergeant in 2011, according to a military spokesman.

Autopsies were under way on Tuesday. A law enforcement source said some of the bodies had stab wounds, some gunshot wounds and some may have had both.

Stone and his ex-wife, Nicole, 33, filed for divorce in 2009 and continued to have a custody battle. Stone asked a court on Dec 5 to grant him custody on an emergency basis, according to court records.