Seven people were injured when a male suspect began stabbing attendees of a "rowdy" Halloween house party in the city's Annex neighbourhood overnight.

Toronto police say they were called to a home on Madison Avenue north of Bloor Street West overnight starting at 11:47 p.m. Thursday for a report of three people stabbed at a house party.

They arrived to find one of the three suffering from serious injuries.

A further search of the area led them to locate three other victims.

Investigators say two of the victims have life-threatening injuries, two have serious injuries, and two others have minor injures.

A seventh victim showed up about 35 minutes later at a hospital and passed out in the emergency room, officers said.

That victim's condition is not yet known.

Police said a suspect was taken into custody by 12:44 a.m.