One man is dead and a woman was taken to hospital with critical injuries after a shooting in the city's south end on Sunday night, and police say no arrests have been made.

Ottawa police were called to a townhome on Patola Private, near the intersection of Albion Road and Cahill Drive, close to the South Keys Shopping Centre, at approximately 7:20 p.m.

Police asked the public to remain indoors Sunday night during an active police operation near the South Keys Shopping Centre. 0:29

According to police and paramedics, a man was shot and pronounced dead at the scene.

A young woman was also shot, and was rushed to the Ottawa Hospital's Civic campus trauma centre in critical condition.

As of 9:30 p.m. about 20 officers remained on the scene, including a police negotiator. One hour later, police said a suspect was still barricaded inside a home.

Ongoing police operation underway on Cahill Dr. for barricaded person. Road closures in place. Please avoid area. Residents are asked to remain indoors and follow the instructions of police and emergency workers. Updates will follow. <a href="https://twitter.com/DutyInspector?ref_src=twsrc%5Etfw">@DutyInspector</a> —@OttawaPolice

No one was barricaded, police later said

They urged people living nearby to stay inside and follow officers' instructions, and some were asked to leave their homes as a safety precaution.

Just before 1 a.m. Monday, police said the operation had concluded and that people could return to their homes and normal activities.

This incident has concluded. Anyone who had sheltered in place may resume activities. Thank you for your patience. Roads will re-open shortly. 857 <a href="https://t.co/0qWpoGtwIa">https://t.co/0qWpoGtwIa</a> —@DutyInspector

No one was arrested, and police said it turned out that there hadn't actually been a barricaded person in the home.

'Only as good as the information that comes to us'

Neighbours told CBC News they had heard a loud argument at a barbecue prior to the shooting.

Ottawa police Sgt. Peter Van Der Zander is encouraging residents to come forward with more details.

"We're only as good as the information that comes to us," he said in an interview at the scene Sunday night.

"This is a complex investigation. This will be time consuming. This investigation will not be concluded today, tomorrow, this week or probably even this month. This is the type of investigation that will take time."