LOS ANGELES (CBSLA.com) — Three massive public events this weekend are each expected to draw tens of thousands of people, so officials are busy stepping up security in the aftermath of the Boston Marathon bombings.

The Toyota Grand Prix of Long Beach, the L.A. Times Festival of Books and CicLAvia to the Sea all happen this weekend – in addition to the usual schedule of sporting events.

“Our trains have direct service to all of the events this weekend,” Metro spokesman Dave Sotero said.

Metro officials say not only have they stepped up service to each event, security has been heightened on their trains.

“The LA County Sheriff’s Department is in charge of Metro system security and they have already stated that they are on a heightened alert and they are intensifying patrols on the Metro system,” Sotero said.

Sotero says armed personnel have begun patrolling Union Station with bomb-detecting K9 units and are conducting random bag searches at the busy train station.

Three people, including an 8-year-old boy, were killed Monday after two bombs exploded at the finish line of the Boston Marathon. More than 180 people have been injured, many catastrophically.

Jim Michaelian, president and CEO of the Grand Prix Association of Long Beach, issued the following statement regarding event security for the annual event, starting Friday.

“The Grand Prix Association of Long Beach will be working in conjunction with the Long Beach Police Department, Fire Department, city and other agencies in taking appropriate measures to provide for the safety of our fans, workers and participants at the Toyota Grand Prix of Long Beach this weekend.”