ALAMO, Calif. -- A 3.1 magnitude earthquake with an epicenter near Piedmont jolted the East Bay Friday afternoon at approximately 4:19 p.m., according to the United States Geological Survey Web site.

The quake was centered one mile northeast from Piedmont not far from the Warren Freeway and three miles north northeast of Oakland, according to the U.S. Geological Survey. It had a recorded depth of about 8 miles, the USGS said.

Bay Area Rapid Transit officials said there would be temporary systemwide delays of about five minutes Friday evening but they did not know how long the delays would last.

So far there are no reports of damage or injuries.