This was reported by RIA Novosti with reference to a preliminary statement by the subcommittee on COVID-19 of the WHO Global Advisory Committee on Vaccine Safety.
"Based on current information, a causal relationship between the vaccine and the occurrence of blood clots with a low platelet count is considered likely but not confirmed," the WHO said.
The statement notes that specialized research is needed "to fully understand the potential link between vaccinations and possible risk factors."
Earlier, the European Medicines Agency announced the need to include cases of blood clots on the list of rare side effects of the Vaxzevria vaccine (formerly known as AstraZeneca).