BOSTON (AP) — Riders on the MBTA are being subject to enhanced security, including random bag searches, in the aftermath of the Boston Marathon explosions.

MBTA Police Chief Paul MacMillan says the random searches at stations are part of an attempt to reassure passengers that everything is being done to protect their safety. He says passengers have been cooperative and understanding.

MBTA spokesman Joe Pesaturo says nothing suspicious was found on Tuesday and service has been running at or near schedule. The Copley subway station nearest the blast scene remains closed.

The MBTA is part of an FBI-led joint investigation into the bombings that killed 3 people and injured more than 170 others.