Pipe bomb explodes along route of Jersey Shore charity run

A pipe bomb exploded in a New Jersey beach town on Saturday along the route of a charity road race to benefit military veterans and their families, but no injuries were reported in what authorities believe was a deliberate attack.

An explosive device went off at 9:35 a.m. local time in a plastic garbage container on the route of the five-kilometre race in Seaside Park, a resort about 129 kilometres south of New York City, the Ocean County prosecutor's office.

No damage to surrounding structures was reported after the blast.

Even so, the explosion stirred dark memories of the deadly blasts at the finish line of the Boston Marathon in 2013 that killed three people and wounded more than 260 others.

'It's obvious it was meant to affect the run'

Authorities immediately cancelled the race, the Seaside Semper Five 5K, closed the beach and the surrounding blocks and evacuated dozens of homes in a search for more devices.

"It's obvious it was meant to affect the run, the fact that it went off at 9:35," five minutes after its scheduled start, Al Della Fave, a spokesman for the Ocean County Prosecutor's Office, said in an interview on CNN.

The charity run was organized to benefit military veterans and the families of those lost in military service. The run's name is a reference to Semper Fidelis, Latin for "always loyal," the motto of the U.S. Marine Corps.

Asked if marines and their families had been targeted, he said, "I think we can assume that, considering the location of the device right along the run route where, if it was just a matter of minutes in terms of difference, there would have been a good number of people running past that explosive device."

The garbage can contained several "pipe bomb-type devices" wired together, Fave said.

"The one went off and the others did not," he said. Law enforcement authorities said they did not know the motive for the blast.

"What the intentions of the individual, we don't know yet, whether it was criminal or terroristic," Della Fave told CNN.

Thousands of runners were set to participate

The explosive went off near the boardwalk by the intersection of Ocean Avenue and D Street, authorities said.

According to a course map for the race posted online, runners would have passed near the intersection twice: once 1.12 kilometres into the race and again 1.12 kilometres from the finish.

About 5,000 people were set to run the 5K race in Seaside Park, a family-oriented resort known for its beachside boardwalk, a local NBC affiliate reported.

The race was to begin at 9.30 a.m. but was delayed because of late sign-ins, the television report said.

A 1.6-kilometre "fun run" was due to begin at 9 a.m. It was not immediately clear whether it got off on schedule, nor whether its route would have taken runners near the site of the blast.

Authorities were evacuating about 30 homes, many of them summer homes, near the site of the explosion, Ocean County Sheriff Michael Mastronardy said in a phone interview.

He said authorities were in the initial phase of their investigation and trying to keep people safe. Authorities, including the FBI, were in the town and were investigating the possibility there was at least one other unexploded device, the officer said.

A seafood festival at nearby Point Pleasant Beach scheduled for Saturday was cancelled after the explosion, apparently as a precaution, the county sheriff said on Twitter.

At the 2013 Boston Marathon, two brothers of Chechen ethnicity who professed allegiance to Islamist militants planted homemade bombs near the finish line of the renowned race. The subsequent explosions killed and maimed dozens of bystanders in the most high-profile attack on U.S. soil since Sept. 11, 2001.

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