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MILFORD TOWNSHIP, Pa. (CBS) — Officials in Upper Bucks County are urging residents to be cautious after learning there still may be devices that failed to explode and could still be live following a series of mysterious blasts earlier this year.

bomb material 11 Officials Warn Upper Bucks County Residents Some Unexploded Devices Could Still Be Live Following Mysterious Blasts

(credit: Bucks County DA’s Office)

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David Surman Jr. and Tina May Smith have been charged with numerous counts following reports of 30 explosions from April to late June. Authorities say many of those blasts occurred within a few miles of the couple’s home on the 2400 block of North Old Bethlehem Pike in Milford Township.

david surman jr mugshot Officials Warn Upper Bucks County Residents Some Unexploded Devices Could Still Be Live Following Mysterious Blasts

“As always, our number one priority is to make sure everyone in Bucks County is safe, and we are sharing this information with that priority in mind. This is more an FYI than an SOS,” said Bucks County District Attorney Matthew Weintraub. “Nonetheless, we will continue to do our best to protect you by working hard to find any unexploded devices that may remain. If you find something suspicious, please do not investigate it on your own. Call 911.”

“It’s concerning because you are afraid some child might find them or stumble upon them or anybody in general but you feel more for a child,” said John Colligan of Quakertown.

There have been no reports of explosions related to the investigation since Surman was arrested on June 28.

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Authorities say when they raided Surman’s home, they found four bombs, a host of chemicals used in the assembly of bombs and 10 firearms. They say they also found drug paraphernalia and child porn.

bomb material 2 Officials Warn Upper Bucks County Residents Some Unexploded Devices Could Still Be Live Following Mysterious Blasts

(credit: Bucks County DA’s Office)

Any residents who believe they may have found an unexploded bomb are asked to call 911. Anyone who believes they have information that could help investigators is urged to call the FBI at 1-800-CALLFBI and select Option 4 on the menu.