NEW YORK (AP) — Prosecutors say a Bangladeshi immigrant charged in a failed pipe bombing in the New York subway system told a prison guard after his arrest that "more is coming."

Prosecutors made the allegation in papers filed today in Manhattan federal court.

Ullah 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.

The government was responding to a request by defense lawyers that a judge dismiss one of six counts facing Ullah. He has pleaded not guilty.

Authorities say Ullah taunted President Donald Trump on Facebook before the attack. The Republican president later demanded tightened immigration rules.

Prosecutors say Ullah wanted to avenge U.S. aggression toward the Islamic State group. The pipe bomb never fully exploded.