NEW YORK — A Bangladeshi immigrant charged in a failed pipe bombing in the New York subway system told a prison guard and a law enforcement officer after his arrest that "more is coming," prosecutors said Tuesday.

Akayed Ullah, 28, was the only person seriously hurt when the bomb went off Dec. 11 in a corridor linking subways under Manhattan's Port Authority bus terminal.

In court papers, prosecutors revealed what they described as unprompted statements Ullah made to law enforcement officers about the attack.

Three days after the bomb partially exploded, Ullah repeatedly warned a law enforcement officer that "more is coming" and urged the officer to "think who will come after me," prosecutors said.

A week later, Ullah began chanting "more is coming" to a guard at the Metropolitan Correctional Center in lower Manhattan, prosecutors said. They added that he then told the officer: "You started this war, we will finish it. More is coming, you'll see."

The statements were revealed in papers filed in Manhattan federal court as the government disputed a claim made last month by defense lawyers that the last of six counts in an indictment must be dismissed.

The count — using and carrying a destructive device to further the crimes of violence charged in the first five counts — carries the potential for a mandatory 30-year prison sentence that must be served in addition to any sentence related to other counts.

Defense lawyers argued that the charge requires that a bomb be used to further a separate crime of violence. They maintained there was no separate crime of violence.

Authorities have said Ullah, who has pleaded not guilty, taunted President Donald Trump on Facebook before the attack. The Republican president later demanded tightened immigration rules.

Prosecutors said Ullah told investigators after his arrest that he wanted to avenge U.S. aggression toward the Islamic State group and had chosen a busy weekday morning to attack so he could terrorize as many people as possible. The pipe bomb never fully exploded.

Authorities say Ullah's radicalization began in 2014 when he started viewing materials online, including a video instructing Islamic State supporters to carry out attacks in their homelands.

His trial is scheduled to start Oct. 29.