A plainclothes transit officer was injured when a flaming paper bag filled with fireworks exploded last night at the base of a stairway entrance to the A/C/E subway station on 43rd Street and Eighth Avenue.

The officer discovered the bag on the floor at around 8:04 p.m. and the bag exploded moments later, leaving the officer with minor leg injuries. The officer was rushed to Bellevue Hospital.

No passengers were harmed.

Police closed off the station and blocked vehicle and pedestrian traffic between 42nd and 44th streets on Eighth Avenue.

Police were investigating who lit the fireworks in the station and were looking for other explosives in the station. Police did not know what kind of firework was detonated.

Bomb squad units and emergency response personnel were dispatched to the scene.

“It was pretty loud for a firework,” said Harry Hutchinson, 27, who was woken by the blast. He was sleeping in his apartment on 43rd Street and Ninth Avenue.

MAN HOLDS OFF MARSHAL WITH GUNSHOTS

A Queens man who owed $2,500 in back rent fired three shots at a city marshal coming to evict him yesterday afternoon in Woodside, police said.

The gunman, identified as Anthony Labaschi of 59-04 Stephen St., fired an additional shot through the door at an emergency service police unit arriving at the scene, and then barricaded himself in his apartment for three and a half hours before a police hostage negotiation team talked him into coming out.

The city marshal, Edward Guida, was not hit by the shots and no one was injured during the standoff with police. Marshal Guida had approached Mr. Labaschi’s apartment in Ridgewood with the building’s landlord, preparing to serve an eviction notice after seven months of unpaid rent.

Emergency police units swarmed the intersection of Myrtle Avenue and Stephen Street while Mr. Labaschi, 64, locked himself in his apartment. He was armed with a .38-caliber Smith and Wesson handgun. Police evacuated area residents and local business owners and told others to stay in their apartments, avoid their windows, and lock their doors.

Mr. Labaschi emerged shortly before 4 p.m. wearing a black T-shirt and jeans. Police handcuffed him and took him to Jamaica Hospital. No charges were filed, pending a psychological evaluation.

Neighbors described Mr. Labaschi as a nice man who kept mostly to himself following the recent death of his mother.

“He’s a good guy, just out on his luck,” said neighbor Tom Damato, who called Mr. Labaschi and tried to persuade him to end the standoff. “I just told him, ‘Don’t hurt nobody and they won’t hurt you.'”

OFFICER INJURED BY VEHICLE

Two suspects were arrested after they crashed their sedan into a highway patrol officer on the FDR Drive and then fled the scene, police said.

The officer was taken to New York Presbyterian Hospital, where he was listed in stable condition with neck, back, arm, and leg injuries.

Two officers were conducting traffic enforcement duties on the southbound FDR Drive and the Triboro Bridge ramp on the Upper East Side when they saw a Volkswagen Jetta driving on the shoulder of the exit ramp to the FDR Drive. The officer attempted to stop the car, which struck one of the officers, according to police.

The officers followed the Jetta, which struck another car and exited the FDR Drive at 106th Street before the officers were able to arrest the occupants.

The driver, Leon Carballo, 26, of 238 E. 89th St., Manhattan, and passenger Danny Santana, 19, of 761 Dawson St., the Bronx, were charged with second-degree assault, reckless endangerment, reckless driving, leaving the scene of an accident, and disobeying pavement markings, police said.

HOMICIDE ARREST IN HARLEM

Police arrested a teenager accused of killing a man in Harlem on Sunday. Courtney Greeley, 17, of 2979 Eighth Ave., Manhattan, was arrested yesterday at 5:24 a.m., police said. Mr. Greeley is accused of shooting a 25-year-old man once in the chest on Sunday at 40 minutes after midnight at West 147th Street. The victim was pronounced dead a half-hour later at Harlem Hospital.