Two water main breaks are causing traffic problems in downtown Toronto.

Part of Bay Street is closed due to a ruptured pipe that police say caused a sinkhole.

Bay is blocked between Queen and Richmond streets, and police expect the closure to last several hours.

Richmond, a one-way street that runs west, was blocked at Yonge Street at one point, but one lane reopened at about 5:20 a.m.

City crews also responded to a water main break in University Avenue's southbound lanes at Dundas Street West.