A mechanical problem has caused Caltrain delays of up to 40 minutes this morning, a Caltrain spokeswoman said.

The delays began earlier this morning when the mechanical problem was reported on a northbound train, spokeswoman Christine Dunn said. 

Northbound train No. 221 was about 40 minutes late as of 9:15 a.m. Southbound train No. 230 was running about 10 minutes late.

All other trains are operating on time.

For trip planning information, riders should call the customer service center at (800) 660-4287.