NEW YORK (AP) — A woman who gave birth under arrest and her boyfriend were facing weapons charges Monday after authorities said they found a substance used to make bombs and papers titled "The Terrorist Encyclopedia" in their apartment in a picturesque Manhattan neighborhood.

Morgan Gliedman, the 27-year-old daughter of a prominent New York City physician, and Aaron Greene, 31, were arrested Saturday after officers with a search warrant discovered a plastic container with 7 grams of HMTD, a highly explosive white powder used in bomb making, police and prosecutors said.

Police Commissioner Raymond Kelly said Monday the substance was powerful, but it was difficult to speculate how much damage it would do in that amount.

Also found in the living room were numerous written items containing instructions on the manufacture of explosive materials and bombs, including a collection of pages that had a cover page entitled "The Terrorist Encyclopedia" and a booklet entitled "Deadly Homemade Weapons," court papers said. No political writings were discovered, and Kelly said the investigation was continuing into whether the couple had any larger plans or ties to any radical groups. They didn't show up on any watch lists.

Investigators also recovered a sawed-off shotgun, a commercial replica of a grenade launcher and ammunition, and chemical precursors to HMTD also were found in the living room, according to police and court papers.

Greene was held without bail after he appeared in state court in Manhattan on Sunday. Gliedman, who was nine months pregnant when she was arrested, went into labor and gave birth to a baby girl named Melanie, police said. She was hospitalized and had not yet appeared in court. It was not clear who will represent her. A call to her family was not immediately returned Monday.

Authorities said both defendants had drug problems.

"The whole situation's sad," said attorney Lisa Pelosi, who represented Greene. She declined further comment. Greene is due back in court Friday.

Greene claimed he was a Harvard graduate, but the university was closed Monday and it was not immediately possible to determine whether he actually attended the school.

Police went to the apartment in Manhattan's Greenwich Village on Saturday morning with a search warrant stemming from a possible credit card fraud by Gliedman, after a tip warning authorities of explosives inside the home. The tip came from a couple who had met Greene and Gliedman in Washington Square Park recently, and said they noticed the cache when they went to their apartment a few weeks ago, Kelly said.

The picturesque street was blocked off Saturday as officers searched the home.