PITTSBURGH — A series of strong thunderstorms this morning has caused flash flooding in Pittsburgh and other areas of southwestern Pennsylvania.

There were numerous reports of streets washed out, including in the suburbs of Castle Shannon and Mount Lebanon, where runoff was heavy off saturated hillsides. Some motorists found their vehicles disabled in the rising water and had to be rescued by bystanders or emergency crews.

The outbound lanes of the Fort Pitt Tunnel in Pittsburgh closed due to flooding, and some light-rail service into the city was shut down by a landslide in Castle Shannon, south of the city.

The National Weather Service had issued a flash flood warning for southwestern Pennsylvania that was set to expire at 9:30 a.m.

There were no immediate reports of injuries or major property damage.