TOKYO — Greece has withdrawn from the Tokyo Olympics artistic swimming competitions after four of their athletes tested positive for COVID-19, the Greek Olympic Committee said on Tuesday.

One athlete tested positive on Monday while another three returned positive tests on Tuesday, ruling the team out and forcing the athletes into quarantine.

"The team from the very first day it entered the village has not come into contact with any other member of the Greek Olympic team for obvious reasons," the HOC said.

All athletes are under tight restrictions once they arrive in Japan as the country struggles with record numbers of infections and the Games are held without spectators.

Tokyo Olympics organizers on Tuesday reported 18 new Games-related COVID-19 cases, bringing the total since July 1 to 294.