Blood still stains the tiles of Sarah Kitney's west Ottawa apartment after a woman says she fought off a man who was sexually assaulting her.

Kitney lives at an apartment building on Elmira Drive and said she was woken up by a knock on her door Thursday morning.

"(There was) a terrified young girl, shocked, just covered in blood - I can see on her face and dripping down her legs," she said, explaining the 19-year-old victim told her she had been sexually assaulted down the hall.

"He had a weapon and he was trying to get her to do sexual favours . . . She didn't go into any details with me."

The victim, who was only wearing a coat, told Kitney she was able to fight off her attacker.

"She had wounds on her hands and they were just defensive," she said.

"I just did the best I could . . . I got her clothes, I got her towels, and just tried to keep her safe."

Ottawa police said they responded to a call at the apartment complex just after 10 a.m., arresting a 56-year-old man.

"From her description, a male was located in the area and was taken into custody - also suffering from injuries," said Sgt. Glenn Gordon of the Ottawa police.

"He was just in some boxers and he had blood dripping down his leg and on his torso," Kitney said. "They escorted him into the ambulance pretty quickly and took him away."

Kitney said the victim and suspect both live in her building, but they didn't know each other - the teenaged victim told her she didn't know the man's name.

Ottawa police continue to investigate and ask anyone with information to contact their sexual assault/child abuse section at 613-236-1222 extension 5944 or Crime Stoppers at 613-233-8477.

With a report from CTV Ottawa's John Hua