Four city police officers were wounded by gunfire last night while they served a search warrant at a North Baltimore rowhouse as part of a drug investigation, authorities said.

The officers - two of them in plainclothes - were rushed by ambulance to the Maryland Shock Trauma Center and were in good condition, said Police Commissioner Edward T. Norris. Three were hit in the leg, and the other was shot in one or both hands as he held a protective body shield, police said.

The gunfire erupted shortly before 9 p.m., as the officers, three of them members of the Northeastern District's drug enforcement unit, attempted to raid the house in the 1000 block of Cameron Road, where police said drug activity was conducted. Police investigated in response to neighbors' complaints about drug activity.

As the officers entered the house, police said, a man fired at them. Neighbors reported hearing bursts of five to 10 shots.

Officers who had surrounded the premises as the raid was staged issued a police radio "Signal 13" alert for help, bringing dozens of other officers to the Cameron Village neighborhood near Woodbourne Avenue and The Alameda.

Within minutes, officers in the police department's Quick Response Team entered the two-story brick dwelling and, according to initial accounts, escorted a man, woman and child away from the scene, and arrested three others, one of whom Norris said was believed to be the gunman.

Early today, standing outside Shock Trauma with Mayor Martin O'Malley and Dr. Thomas M. Scalea, the medical facility's physician-in-chief, Norris said two men and a woman were being questioned by detectives.

Names of the wounded officers were not released. Referring to the officer shot in both hands, Norris praised his courage for continuing to hold the protective shield after his hands went numb as the others got out of the line of fire.

Of the others, one officer was shot in the calf, one in the shin, and the other in the thigh and forearm. None of the wounds was life-threatening, Scalea said, but added that it could be weeks or months before the severity of some of the injuries would be known. It could take several weeks or months for the men to recover, he said.

One was quickly released after treatment, and another was preparing to leave the hospital early today. Another finished surgery to re-establish blood flow to his foot, and the other was entering surgery to relieve pressure in a leg, Scalea said.

The number of city officers shot was believed to be the most in a single incident since 1976, when an 18-year-old sniper barricaded in a house on West Lombard Street killed an officer and wounded five others and a passer-by in an hour-long gun battle. Two of the officers were permanently disabled.

While the injuries last night were not as serious, Norris used them as an example of the dangers facing his lawmen. "It's the nature of the business," he said. "It's a tough town. This is just the way things go. When you're dealing with drug violators, you can expect this sort of thing."

By car and on foot, officers - many with guns drawn - flooded Cameron Road in the minutes after the gunfire, ordering residents peeking through window blinds, and from porches and behind doors, to stay inside. Police cruisers cordoned off a two-block radius of the site as a police helicopter flew overhead, training a spotlight on the ground.

The shooting startled residents of Cameron Road, who said they couldn't recall the last time they heard gunfire on the tree-lined street whose residents range from young families to seniors. The only noise many said they are accustomed to is the cacophony of Chinquapin Middle School children walking by.

"This is why it's so shocking. I was like, 'Oh my gracious!'" said Elfrieda Thomas, who has lived on the street for 14 years.

Thomas was upstairs in her bedroom watching a Harry Potter movie on television, she said, when she heard at least 10 consecutive shots, a pause, and then about 10 more shots. She yelled, "Get down!" to her 13-year-old daughter, who was watching television in the first-floor living room. Within minutes, she said, dozens of police cruisers filled the block and she saw uniformed and plainclothes officers running on foot, shouting to curious residents, "Get back in! Get off the porch!"

Thomas, who lives across the street and a few doors away from the shooting scene, described officers armed with rifles and carrying body shields crouching behind parked cars and trees as the house and neighborhood were searched.

"I've never seen anything like this," said Martha Atkinson, a 25-year resident, as she watched an officer use her 1996 Hyundai Elantra as cover. Atkinson said she was in her bed about 8:45 p.m. when she heard four shots, a pause, then more shots. "I haven't been to the door. I know better than that."

The incident marked the third time this year that a city officer had been wounded by gunfire in the line of duty.

Last week, Officer James Howard of the Northwestern District was slightly injured when his badge deflected a bullet fired by an assailant during a struggle in a dark alley.

In July, Officer Chris Houser, also of the Northwestern, was seriously wounded as he was making a drug arrest. Police said the officer was gunned down from across the street by someone trying to break up the arrest of a cousin.

"We've been very fortunate," Norris said outside Shock Trauma, that none of the officers died.

"This is an extremely dangerous job," the commissioner added. "I don't know where we find people to do this."

Sun staff writer Del Quentin Wilber contributed to this article.