JUN-MIN PARK and SAKURA MURAKAMI THE chief of the Tokyo 2020 organising committee has not ruled out cancelling the Olympics if COVID-19 cases spiked, as more athletes tested positive for the virus and sponsors ditched plans to attend Friday's opening ceremony. Asked at a news conference if the global sporting showpiece might still be cancelled, Toshiro Muto said he would keep an eye on infection numbers and liaise with other organisers if necessary. "We will continue discussions if there is a spike in cases," said Muto. "We have agreed that based on the coronavirus situation, we will convene five-party talks…