THE alleged New York bomber had a deadly Christmas motive when he detonated an explosive device on a bustling subway, it has been revealed.

Akayed Ullah, a 27-year-old Bangladesh immigrant, reportedly told investigators he targeted the area because of Christmas posters that lined the underground tunnel between the bus depot and the Times Square subway, according to the New York Post.

‘He acknowledges he purposely set it off then and there,’ a senior law enforcement official said.

The festive imagery triggered his desire to follow ISIS Christmas propaganda released just weeks ago, which featured a picture of Santa Claus in Times Square next to explosives and the phrase “We meet at Christmas in New York ... soon,” according to terror watchdog group Site Intel.

It is understood Ullah used Christmas tree lights to make the bomb, which also used a length of pipe, a battery and sugar.

Ullah had wires attached to him and was armed with a pipe bomb and a battery pack, which he tried to set off in the subway around 7.20am (11.20pm AEDT) Monday local time, according to police sources.

In disturbing CCTV footage of the incident (which can be viewed in the video player above), the man can be seen walking along a subway tunnel before attempting to detonate his device, before terrified commuters run for their lives.

According to the New York Post, the pipe wasn’t packed tightly enough to explode, so when the festive lights sparked the matches, it just blew the ends off the pipe rather than sending the shrapnel flying.

Christmas tree lights are often used as detonators in homemade bombs — the Boston marathon and London subway terrorists both used the seasonal decor to ignite their charges.

According to the reports Ullah had travelled on the subway from Brooklyn with the bomb strapped to him before detonating it.

CHRISTMAS LIGHTS A TOOL FOR TERRORISTS

Christmas lights have been used by other terrorists in their makeshift devices.

A bucket nail bomb that went off on a crowded London Tube train in September included a detonator made from Christmas lights.

The device could have killed dozens but for a suspected faulty timer.

The Sun reported the timer malfunctioned — setting it off earlier than planned and failing to ignite the main bomb.

The homemade device was described as having “a certain level of sophistication” and also comprised Christmas lights and a circuit board.

Major General Chip Chapman told Sky News at the time: “It seems to be this bomb either malfunctioned or it’s not TATP (triacetone triperoxide), the explosives used by groups like ISIS.

“It’s more like the Boston bomb. It’s almost like a pressure cooker device.”

The 2013 Boston Marathon bombing featured two homemade explosive devices that were detonated 12 seconds apart from one another, killing three and injuring 280.

The pair responsible for the attack used pressure cooker devices — containers packed with explosives and loaded with nails and ball bearings to inflict maximum damage.

The Bostom bombers also used Christmas lights in the devices.

FBI Special Agent Edward Knapp testified at the 2015 trial of the surviving terrorist Dzhokhar Tsarnaev that the lights acted as an “initiator”.

“It’s not that sophisticated,” Knapp said in Boston Federal Court, The New York Daily News reported.

“It’s not too difficult a system to build.”

According to the publication, the instructions were discovered on Tsarnaev’s laptop computer in a document titled ‘How to build a bomb in the kitchen of your mum’.

The article was reportedly from Inspire, an online magazine published by al-Qaeda in the Saudi Arabian Peninsula.

SUSPECT’S FAMILY SLAM AUTHORITIES

Ullah’s family has slammed authorities over their investigation into the suspected terror attack, hitting out over what they say are heavy-handed tactics from law enforcement.

The New York Postreports, the family were “outraged” by the work of investigators, in a statement released on their behalf.

“We are heartbroken by the violence that was targeted at our city today and by the allegations being made against a member of our family,” said the statement read by Albert Fox Cahn, the Legal Director for the NY Chapter Council for Islamic Relations.

“But we’re also outraged by the behaviour of the law enforcement officials who held children as small as four years old out in the cold and who pulled a teenager out of high school classes to interrogate him without lawyer, without his parents.”

It was not immediately clear if the four-year-old or the teenager were related to the suspect.

The family continued to criticise the way the investigation was handled.

“These are not the sorts of actions we expect from our justice system,” the statement read.

“We have every confidence that our justice system will find the truth behind this attack and that we will in the end be able learn what occurred today.”

New York mayor Bill de Blasio said the incident was being treated as a terror attack by one man “who thank God, was unsuccessful in his aims”.

New York Police Commissioner James O’Neill described it a “terror-related incident.”

Governor Andrew Cuomo said of the device: “It was not a sophisticated device, it was a homemade device. He did detonate it, but it did not fully have the effect that he was hoping for. The explosive chemical did ignite. It was in a pipe, but the pipe itself did not explode. So he wound up hurting himself.”

The New York Post reported the alleged bomber was a former New York taxi driver who told investigators he carried out the attack for revenge on recent Israeli actions in Gaza.

“They’ve been bombing in my country and I wanted to do damage here,” police sources quoted the bomber as saying.

CNN reported Ullah had pledged allegiance to ISIS while talking with authorities. That claim is now being investigated.

Ullah suffered burns to his abdomen and hands and was in custody at New York’s Bellevue Hospital.

Local media reported that the suspect was from Bangladesh and lived in Brooklyn, having been in the US for seven years.

The three injured people took themselves to nearby hospitals where they reported minor injuries, including ringing to the ears.

AUSSIES URGED TO BE VIGILANT

Foreign Affairs Minister Julie Bishop has urged Australians travelling overseas to be vigilant in the wake of the New York attack but says there is no need for people to change their travel plans.

“Australians should continue with their travel plans but this is another shocking reminder that a terrorist attack can take place anywhere,” Ms Bishop told Channel Seven’s Sunrise program.

“I urge people to be vigilant, be aware and follow the directions of local authorities.

“I also suggest that people log onto our Smart Traveller website before they travel overseas to get the latest advice.”

AN ‘AMATEUR LEVEL EXPLOSIVE DEVICE’

The device partially detonated below ground inside the subway passageway to the N, Q and R trains near 7th and 8th avenues on 42nd St and was captured on surveillance video.

Police on the scene told News Corp Australia they were “not allowed” to comment.

Following Monday’s attack, commuters told of mass chaos and a “stampede” following the explosion as New York commuters fled in terror through the smoky passageway.

Governor Andrew Cuomo said a bomb in the New York subway was “one of our worst nightmares” but that the reality of the attack was that it was an “effectively low-tech device”.

“There are no known additional incidents or activities...You will see additional NYPD presence throughout the city,” @NYCMayor now. #PortAuthority pic.twitter.com/spYuKrf9Tu — NYPD NEWS (@NYPDnews) December 11, 2017

“There were several injuries, we hope minor and it was handled extraordinarily well,” Governor Cuomo said.

He said disruptions to the train and bus services had been restored. “This is New York and the reality is that we are a target for many who would like to make a statement against democracy, against freedom,” he said.

Snapchat video shows emergency crews outside Port Authority terminal after reports of possible explosion. pic.twitter.com/kMkDLfOgO0 — Ryan Wood (@RyanWoodDFW) December 11, 2017

He said there were no further credible threats against the city and the device was “an amateur level explosive device”.

“We have the best law enforcement on the globe and now are all working together extremely well,” he said.

Emergency Services Rush to New York's Port Authority After Explosion. Credit — Facebook/tommy Mazza via Storyful Emergency Services Rush to New York's Port Authority After Explosion. Credit — Facebook/tommy Mazza via Storyful

Port Authority is the largest bus terminal in the United States with about 232,000 commuters passing through each day.

The peak hour explosion plunged Manhattan’s traffic into gridlock, with multiple streets in mid-town New York closed.

NEED FOR IMMIGRATION CHANGE ‘HIGHLIGHTED’

President Donald Trump says a bomb blast in Manhattan highlights the need for an immigration overhaul.

Mr Trump said Monday that the U.S. “must fix its lax immigration system, which allows far too many dangerous, inadequately vetted people” into the country.

The Republican president points to his controversial travel ban as an example of the kind of policy that needs to be put in place. And he’s calling on Congress to end “chain migration,” in which family members are permitted to join relatives who have immigrated.

Roads blocked off at 42nd and 7th Ave after explosion at Times Sq pic.twitter.com/Ldo7r2XhHE — Lena (@lmcbtx) December 11, 2017

He also says people convicted of terror acts “deserve the strongest penalty allowed by law, including the death penalty in appropriate cases.” The only person seriously wounded Monday was the suspected bomber.

President Donald Trump was briefed on the explosion, said White House spokeswoman Sarah Huckabee Sanders.

Ullah reportedly came to the US from Bangladesh in 2011 on a visa for children of US siblings, the Department of Homeland Security confirmed, CNN reported. As such Ullah is a lawful permanent resident or green card holder.

Lots of emergency responders on 8th Ave. between 42nd and 43rd streets. pic.twitter.com/AdVuduoAoU — Niraj Chokshi (@NirajC) December 11, 2017

The bombing, which former New York Police Commissioner Bill Bratton said he had been told by sources in the department the explosion was an “ISIS-inspired attack”, would be New York City’s second ISIS-inspired attack in less than two months.

On October 30, a man drove his rented truck down a cycle path along the Hudson River, killing eight and injuring 11 others.

Ullah came to the U.S. on an F43 visa, issued to him through his family connection to an American citizen. The American immigration system allows citizens to apply for certain relatives — spouses, children, parents, siblings and their spouses and minor children — to be allowed to come and live in the U.S. The visas fall under different preferences, or categories; siblings of U.S. citizens come in the fourth preference, the F4, and their children come under F43s.

Those who favour restrictions on immigration are in strong opposition to that kind of linked migration. It’s an issue that’s been brought up in proposed immigration reform legislation before. U.S. Sen. Tom Cotton, of Arkansas, and U.S. Sen. David Perdue, of Georgia, both Republicans, have most recently proposed the RAISE Act, which would limit the number of permanent-resident visas and do away with the ability of citizens to bring over relatives other than spouses and minor children. Immigrant advocates have called the bill an attack on immigrants.