Police say a man accused with his girlfriend of keeping bomb-making materials in their Greenwich Village apartment had told acquaintances he planned to blow up the Washington Square Park arch.

Police spokesman Paul Browne said the acquaintances told investigators they saw Aaron Greene trigger an explosion after sprinkling a white powder in the park.

Browne told The New York Times police believe the powder was HMTD, a bomb-making material they found in the couple’s apartment last month.

The new details emerged after police searched the Orangeburg, N.Y. home of Greene’s friend. They found 21 guns, brass knuckles, two stun guns and a switchblade knife. Browne said police went there after Greene said he had given some of his weapons to the man.

Greene’s lawyer declined to comment.

(AP)