
A deadly pipe bomb exploded along a route where thousands of runners were due to take part in a charity run in Jersey.

More than one thousand spectators, including war veterans and small children, had gathered just a few blocks from the blast in Jersey Shore town on Saturday afternoon.

Two unexploded pipe bombs were found in a garbage can near the event 5km run which sought to raise money for marines and sailors.

No injuries have been reported but bomb-sniffing dogs have continued to look for more bombs in the area, NJ.com reported.

Later on Saturday night, at least 29 people were injured when another explosive device hidden in a garbage can was 'deliberately' detonated in New York's affluent Chelsea neighborhood. Authorities have ruled out a connection between the two blasts despite their similarities.

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A pipe bomb set in a garbage can (pictured) exploded in Seaside Park, New Jersey, before thousands of runners were due to take part in a charity 5K race to benefit marines and sailors

More than one thousand spectators, including war veterans and small children, had gathered just a few blocks from the blast

At least 29 people were injured when another explosive device hidden in a garbage can exploded in New York's affluent Chelsea neighborhood

The start of the race was delayed after authorities were alerted to an unattended backpack.

The pipe bomb near D Street exploded about 9.30am - the exact time runners were due to pass that location.

'It was a big puff of smoke, fairly large,' said Adam Carswell, who was registered to run the race, to NBC 4 New York.

A rep for the Ocean County Prosecutor's Office says the device was too sophisticated to have been a prank.

'We don't know what this individual's agenda is,' Al Della Fave told ABC News.

'We did find that within that same garbage can there were other devices wired to the one that did explode,' Della Fave told CBS.

Pieces from the explosion were blown out as far as 150ft.

Officials say runners (pictured in last year's event) had been scheduled to pass by the area around the time the blast occurred

A rep for the Ocean County Prosecutor's Office says the device was too sophisticated to have been a prank (pictured, authorities on the scene)

The pipe bomb near D Street exploded about 9.30am - the exact time runners were due to pass that location (pictured, sniffer dogs hunting for more explosives)

Police patrolled the area in Jersey Shore town where the pipe bomb went off, close to a route where thousands of runners were due to run

Mother and daughter, Audrey King, 46, and Alina, 8, embrace near the scene of the pipe bomb explosion in Jersey

Event organizers canceled the race because of a suspicious backpack found at the site

'I thought it might have been an explosion of some sort or a sonic boom,' Lauren Rispoli, who heard the explosion from her bed, told NBC 4 New York.

Officials say runners had been scheduled to pass by the area around the time the blast occurred.

'Out of extreme precaution, this year's Seaside Sempre Five has been canceled due to an unidentified suspicious backpack found at the race site,' event organizers said Saturday morning.

'The safety and security of our participants, spectators, staff and volunteers is of utmost importance.

The race - the third annual Semper Five run - was canceled.

The area remained 'on lock down while bomb dogs search of additional devices' into the afternoon, the county prosecutor's office said in a statement.

The pipe bomb was in a garbage can near D Street when it exploded. Authorities immediately cleared the boardwalk and beach area

The 5K was organized by the MARSOC Foundation, which is a nonprofit that raises money to support active duty and medically retired Marines and Sailors, as well as their families

The blast occurred on N Ocean Ave near D and E Streets, where the runners would have been had the race not been delayed

Would-be runner Cathy Howath, 50, said it was a 'blessing in disguise' that there were delays at the start of the race.

One of them was for a blue backpack near a media tent.

'They kept making the announcement, "There’s an unclaimed, blue backpack by the News 12 tent and the radio station tent. If this is your backpack, please come and claim it" — it was repeatedly,' Howath told USA Today.

'It was a blessing in disguise, because the pipebomb would have gone off when the 5K was going,' Howath added.

'It was a blessing in disguise, because the pipebomb would have gone off when the 5K was going,' Howath added.

The FBI and the Department of Homeland Security are investigating, alongside a number of other agencies.

'We've evacuated within a four-block perimeter,' Della Fave told NJ.com.

Last year's Semper Five Run drew thousands of runners (pictured). This year's race was due to attract a similar number of participants

'Traffic into Seaside Park is closed, but (drivers) are allowed to go to Seaside Heights.'

It wasn't clear when the boardwalk and beach will reopen.

The 5K was organized by the MARSOC Foundation, which is a nonprofit that raises money to support active duty and medically retired Marines and Sailors, as well as their families.

The second blast on 23rd Street and Sixth Avenue in Chelsea is also believed to have come from a dumpster and could have come from an explosive device.

The Fire Department reported that there were at least 29 people wounded when the deafening blast ripped through the busy area at 8.30pm.

The NYPD Special Ops tweeted that they are investigating a 'possible' second device that was found at 27th Street and Sixth Avenue, which is just four blocks away from where the blast occurred.

The second blast in the Chelsea neighborhood (pictured) in New York city ripped through the busy area at 8.30pm

The blast shattered the windows of a nearby apartment building and injured at least 29, at least one of whom is in a critical condition

The NYPD Special Ops tweeted that they are investigating a 'possible' second device

New York Mayor Bill de Blasio said during a press conference that injuries 'are significant but at this point we can confirm that none of those injured are likely to die'.

'There is no evidence at this point of a terror connection.' De Blasio also said it is 'too early to determine' if the incident in New York is connected to the explosion in New Jersey.

However, the mayor said: 'We believe that it was an intentional act.'

He added that investigators are tracing every lead but it's still too early to give any details of the investigation.