Isis has claimed responsibility for the deadly Manhattan terror attack carried out by Uzbek national Sayfullo Saipov, who killed eight people by ramming a truck into a crowd in Tribeca neighbourhood on Tuesday (31 October).

The militant group said in its weekly newsletter, Naba, that Saipov is a "soldier of the caliphate," according to the SITE Intelligence Group. SITE added that the Islamist jihadist group only claimed to have inspired the truck attack and not coordinated it.

Meanwhile, Saipov, who is currently in a hospital after being shot in the abdomen by US security forces, admitted to being inspired by watching Isis videos on his cell phone. He also told investigators that he intended to cause a massive casualty and thus, chose Halloween day as the day of the attack.

He was detained before he could carry out the next phase of his planned assault on the Brooklyn Bridge in New York City.

The Isis follower told US officials that he was proud of killing eight people and injuring nearly a dozen others. He reportedly requested the officials to put up an Isis flag in his hospital room.

Police reports stated that Saipov, 29, was driven to carry out an attack after watching a video in which Isis founder Abu Bakr al-Baghdadi exhorted Muslims in the US and elsewhere in the world to seek revenge against the killing of Muslims in Iraq.

Police found knives inside Saipov's truck and notes praising Isis. Court documents stated that two cellphones were also recovered from him.

A law enforcement source told CBS News that numbers on the phones were tracked to "sympathisers of a radical cause" who were already on New York police radar. The source added that Saipov made calls to some of those numbers on "the day of the attack".