NHK has learned that about 3,500 out of more than 40,000 "City Volunteers" recruited to act as city guides during the Olympic and Paralympic Games in Tokyo have withdrawn.
This is in addition to the approximately 10,000 out of 80,000 "Field Cast" volunteers, due to work at event venues and the athletes' village, who had withdrawn by Tuesday.
Nine out of the 11 prefectural governments that recruited City Volunteers submitted their withdrawal numbers.
Chiba Prefecture topped the list with 1,083 withdrawals by the end of last month, followed by Miyagi with about 800 and Fukushima with about 630.
The total is expected to increase when Tokyo and Saitama Prefecture confirm their numbers.
The prefectures say many volunteers' life situations, such as their work or studies, have changed since the games were postponed.
They say many withdrew because of concerns about the spread of the coronavirus.
Some said they no longer had any reason to participate as there will be no overseas spectators. Others were worried about public opinion, with municipalities split over holding the games.
The prefectures say the withdrawals will not affect the running of the games. They say they will work to ease volunteers' anxieties by explaining during training sessions the measures being taken to prevent infections.