Heavy rains caused flash flooding across the Boston metro area Saturday, stranding cars and causing damage, the National Weather Service reported.

No injuries were immediately reported.

Flash flood warnings were issued for four counties in eastern Massachusetts, and 2 to 4 inches of rain fell in the region, according to the weather service.

There were several reports of cars getting stuck in floodwaters, particularly in the Somerville area, northwest of Boston, where the weather service said at least five vehicles were stranded underneath the Assembly Square Underpass.

Video from CNN affiliates WHDH and WCVB showed the vehicles fully submerged beneath the underpass. Drivers had to be rescued from their cars when the tunnel filled with up to 18 feet of water, according to an off-duty police officer involved with the rescue efforts. The officer told WCVB that the water was heavily mixed with sewage.

The flooding also forced the closures of at least two bridges. Witnesses told WHDH that cars were also submerged around the bridges and residents waded through water up to their knees. Some locals said they helped direct traffic since lights were knocked out by the storms.

The bad weather also disrupted travel for the Boston area transit system.

Joe Pesaturo, a spokesman for the Massachusetts Bay Transportation Authority, told CNN affiliate WCVB that there were weather-related delays during the afternoon, including the suspension of rail service in one area due to water on the tracks