Over 60 of the officers were deployed in today's race in response to concerns over threats of terrorism.
They wore white vests bearing the word "POLICE." Each member ran about 10 kilometres while carrying anti-terrorism gear in small backpacks.
Tokyo has been on edge following the slaying of two Japanese hostages by the Islamic State group last month.
Islamist militants threatened Japanese people everywhere after the slayings.
Over 36,000 runners took part in the race as organisers were eager to show that Tokyo remains a safe place to hold major sporting events.