Organizers of the Tokyo Marathon, which will be held this Sunday, have promised improved security following the killing of two Japanese hostages by the Islamic State group earlier last month.
"We have held anti-terrorism drills and have worked closely with the police agency so we are confident of delivering a safe race," said race president Koji Sakurai.
Around 30,000 runners are estimated to participate in the race through the streets of Tokyo. Police will be among those runners as part of new security measures.
More than 10,000 security personnel, including members of the Metropolitan Police Department, will be on the watch for possible terrorist attacks on Tokyo Marathon 2015.
Islamic State militants threatened Japanese people everywhere after the killing of two Japanese hostages last month.