A cyclist is seriously injured after colliding with an open car door near Kensington Market on Wednesday evening.

The collision occurred shortly before 9 p.m. at Dundas Street West and Denison Avenue, near Bathurst Street.

A man, believed to be in his 30s, was riding eastbound when he slammed into an open U-Haul truck door before striking the pavement, Toronto police Const. Jenniferjit Sidhu said.

The victim was not wearing a helmet when he was hit, Sidhu added. 

He was rushed to a trauma centre where he remains in life-threatening condition, according to paramedics.

The driver was apparently jumping out of the U-Haul truck to return it at a rental centre across the street, when he opened his door onto the cyclist, witnesses said. 

No charges have been laid at this time. He is cooperating with police. 

Investigators have closed Dundas Street West in both directions between Bathurst Street and Spadina Avenue.

The TTC 505 Dundas streetcar is diverting both ways in the area via Spadina Avenue, College Street and Bathurst Street, due to the collision. 

There is no word on when the roadway is expected to reopen.