Boston terrorism suspect
Law enforcement officers gather on a residential street in Everett, Massachusetts, on 2  June 2015 in connection with a man who was shot dead in Boston after coming at officers with a large knife when they tried to question him as part of a terrorism-related investigationREUTERS/Brian Snyder

A New England man in prison on terrorism charges reportedly planned with others to conduct beheadings in the US, federal prosecutors said on 21 April. Nicholas Alexander Rovinski, who was arrested in June 2015, "has attempted to recruit people to assist" in a plan "to commit violent attacks in the United States and to decapitate non-believers", a superseding indictment revealed.

The 25-year-old from Warwick, Rhode Island, was one of three New England men to be accused of plotting to behead Pamela Geller, a New Yorker who organised the Draw Muhammad contest in Texas in 2015, NBC News reported.

In court documents, prosecutors revealed that 21-year-old Junaid Hussain, a British militant, had been communicating with 26-year-old Usaamah Abdullah Rahim of Roslindale, Massachusetts, about the attack on Geller. However, Rahim reportedly changed his mind and instead decided to attack police in Boston, the FBI said.

Rahim was shot and killed in June as he prepared to board a bus armed with a long knife. Meanwhile, Hussain was killed in August 2015 in a drone strike in Raqqa, Syria, the de facto capital of the Islamic State's (Isis) so-called caliphate, The Washington Post reported

The FBI had been able to pick up Rahim confirming to a third man, 26-year-old David Wright of Everett, Massachusetts, that he had changed his mind and decided to "go after the boys in blue". According to prosecutors, Rovinski met Wright online and the duo along with Rahim began discussing the need to commit violence in support of the IS.

The FBI said the three planned Geller's beheading on a secluded beach in Rhode Island in May 2015, just two days before Rahim was killed. NBC News noted that authorities said Rahim also considered launching an attack on Boston's July Fourth celebration on the Esplanade.

The indictment revealed Rovinski "wrote letters to Wright describing ways they could continue to execute their plans to take down the United States government and decapitate non-believers". However the indictment did not reveal how the terror suspect attempted to recruit people while incarcerated.

Wright also reportedly drafted documents for what he referred to as a "martyrdom operations cell" and used the internet to search information on weapons, tranquilisers and the creation of secret militias in the US, prosecutors said. The two men have pleaded not guilty to charges of terrorism and obstruction of justice. Rovinski and Wright are scheduled to head to trial in February 2017.