US law enforcement and intelligence agencies are concerned about copycat vehicle-ramming attacks following the New Year’s Day attack in New Orleans by a US Army veteran, according to a US law enforcement intelligence bulletin published on Friday.The bulletin was issued a day after the Federal Bureau of Investigation (FBI) said that Shamsud-Din Jabbar, a 42-year-old Texas native, was “100% inspired” by the Islamic State (IS) group to drive a truck into New Year’s Day revellers in New Orleans, killing at least 14 people and injuring dozens of others.Jabbar, who flew an IS flag from the rear of the truck he had rented, subsequently was killed in a shootout with police.The FBI, Department of Homeland Security and the US National Counterterrorism Centre “are concerned about possible copycat or retaliatory attacks”, said the intelligence bulletin published by the three agencies and reviewed by Reuters.Such attacks “are likely to remain attractive for aspiring attackers given vehicles’ ease of acquisition and the low skill threshold necessary to conduct an attack”, said the bulletin issued to US law enforcement agencies.The bulletin noted that as of Thursday, the IS had not claimed responsibility for the New Orleans attack.However, the group’s online supporters celebrated it and a December 20 vehicle-ramming in Germany even though that incident did not appear to have been IS-inspired, it said.Other online users have cited those attacks to make “general calls for violence against specific groups, such as immigrants or Muslims”, the bulletin continued.The IS has continued promoting its propaganda and recruiting adherents online despite suffering serious losses to a US-led military coalition that recaptured the “caliphate” the militants overran in Syria and Iraq in 2014.The bulletin urged law enforcement personnel and private security firms to be aware that in many previous cases attackers who rammed vehicles into crowds were armed and continued their attacks with guns or edged weapons.The January 1 incident in the packed French Quarter of New Orleans was the seventh attack in the United States since 2001 that was inspired by a foreign extremist organisation, the bulletin said.The use of “edged weapons” and firearms has been more common in such attacks but vehicles could present a growing threat, it said.US-designated foreign terrorist organisations and “supporter media groups” had released videos, posters, and chants calling for attacks “during the winter holidays generally and New Year’s celebrations specifically”, the bulletin noted.On December 30, “a pro-ISIS media unit” encouraged attacks against New Year’s Eve celebrations in the US and coalition countries by “posting videos highlighting past ISIS attacks and instructing supporters to further incite violence”, it said.President Joe Biden’s administration is keeping President-elect Donald Trump and his transition team apprised of the investigations into the New Orleans attack and an explosion the same day outside the Trump Hotel in Las Vegas, a source familiar with the discussions said.A lack of security clearances among transition team members was not an issue, said the source, noting that much of what is known has been made public.Marco Rubio, Trump’s nominee for secretary of state and Mike Waltz, his incoming national security adviser, already have clearances as members of Congress who served on key intelligence committees.Trump’s incoming chief of staff Susie Wiles also has a clearance and can be briefed, according to a source familiar with the matter.