A woman suffered serious stab wounds in an attack last night near her home in the Dupont Circle-Logan Circle area of Northwest Washington, but several people nearby jumped on the attacker, wrested away his knife and held him down until police arrived.

One of the victim's neighbors, a 31-year-old man who declined to identify himself, said he had just brought his groceries into his home on Corcoran Street NW when he heard a commotion and rushed out to the street corner.

The woman's shirt was soaked with blood after being stabbed, he said. Passersby had intervened and when police arrived at 15th and Corcoran streets about 8:30 p.m. after a flurry of 911 calls, officers found a man being held down.

"The guy was being restrained by a bunch of neighbors," the witness said. "It took five guys on top of him to get him to stop."

The woman, who police said was in her twenties, was transported to a hospital, where she underwent surgery. She was listed in serious but stable condition last night with stab wounds to the upper body, police said. The witness said the woman was alert and talking at the scene.

Investigators where trying to determine whether the woman knew her assailant or was being robbed or attacked randomly. Officers recovered a folding pocketknife, a police official at the scene said.

Officers held a shirtless man in custody for several minutes. He later was transported to Howard University Hospital with minor injuries sustained in the scuffle with bystanders.

In August, a waiter was fatally shot several blocks away, in the 1800 block of R Street NW, as he walked home after leaving his job about 2:30 a.m.