WASHINGTON, April 23 — Gunfire erupted near an elite prep school in an upscale part of Washington, D.C., today, leaving three people wounded as police locked down the surrounding area and conducted a door-to-door search for the assailant.

An eyewitness told local television station WUSA-TV he heard rapid-fire shots lasting about a minute, and saw a woman running out of a building who appeared to have been grazed by gunfire, followed by other individuals who were apparently wounded.

The eyewitness said he saw other people on the street taking cover behind parked cars and pointing up to a balcony where they presumably believed the gunshots were fired.

Authorities said they had no motive for the shooting, which took place in the Van Ness neighbourhood of Northwest Washington along Connecticut Avenue, a major thoroughfare through the city.

Two of the victims, a man and a woman found wounded near the Edmund Burke School, a private preparatory academy, were hospitalized in critical but stable condition, and a juvenile victim suffered a minor gunshot wound, according to Assistant Police Chief Stuart Emerman.

He said police fanned out across the neighbourhood looking for possible perpetrators, but had no immediate description of any suspect. Emerman said several individuals seen fleeing the scene were briefly detained for questioning but none were believed to have been involved.

"I do not believe that we have any suspects at this time detained,” Emerman said.

"We’re looking for any suspect or suspects. We do not have a motive at this time,” Emerman told reporters. "We do not know the full details of what took place. But we continue to ask the public to just steer clear of the area as we continue to investigate.”

Deaven Rector, 22, a law student, told Reuters he lives in the AVA Van Ness apartment building where he believed the shots originated and heard three bursts of gunfire.

"Right now the police have secured the area, and it’s safe, but the fact that this type of chaos can be caused by a maniac on a regular day... the kids were about to get out of school,” he said.

Jennifer DiGiacinto told Reuters she was at home working when she learned of the shooting from a text message sent by her son, an 11th grader at the Burke School.

"He said, ‘There’s something bad happening, I need you to turn on the news.’ I said, ‘Why, what’s happening?’ And he said, ‘Gunfire, I’m under a desk, we’re barricaded in.’"

"This is unheard of,” she said. "But just because you live in Washington, D.C., doesn’t mean you’re going to avoid what’s happening elsewhere. So this is part of our culture now, isn’t it? And sad.”

News footage on local television showed Connecticut Avenue blockaded by emergency vehicles. Dozens of police vehicles, with flashing lights, were parked outside the school building, as police in full tactical gear and some in camouflage assembled nearby.

Local NBC affiliate WRC-TV aired footage showing people being evacuated from a nearby building and running down a sidewalk, some with their hands raised.

"It was madness. I mean, it’s just unbelievable,” Jade Moore, an Edmund Burke parent, told local ABC affiliate WJLA-TV of the incident, which she said left her daughter huddled inside a classroom until police escorted her and other students to a safer part of the campus. "You know, you think they’re safe, but you’re not safe anywhere.”

The affluent neighborhood also is home to several foreign embassies, Howard University School of Law, and the Van Ness campus of the University of the District of Columbia, which said on Twitter that it had been placed on a security lockdown.

A second well-known prep school, the Sidwell Friends School, also was reported by local media to be on lockdown. — Reuters