Police surveillance of the Church St. area in Amsterdam Monday evening led to two drug arrests and seizure of crack cocaine and 30 bags of heroin, police announced Monday.

Detectives were conducting surveillance in the area of Church St. at around 4:00 p.m. Monday when they observed an apparent drug exchange.

Officers stopped Zachary Obrien, 24, of Milton Ave., near the Fourth Avenue Bridge, where police say he agreed to be patted down. Police found three packages of heroin on him and arrested Obrien.

During booking, an officer noticed Obrien reach in his pants, grab an item and swallow it. Officers were unable to retrieve what he swallowed, police say, but Obrien was kept under observation until he could be seen by the judge.

Police also found on Obrien a key to the room at the Valley View Motor Inn, where officers found 24-year-old Kenneth Thomas of Bronx, NY. Thomas signed a waiver to let officers search the room, according to Det. Lt. Thomas DiMezza, and police found a substantial amount of crack cocaine and about 30 bags of heroin.

Police also seized several hundred dollars in cash.

Both men were arrested and charged with felony third-degree criminal possession of a controlled substance.