The three, a Polish diplomat, his wife and a Czech diplomat, were taken to a hospital run by the interior ministry in the Polish capital after their plane landed on Sunday.
Last month, a Polish diplomat suffering from COVID-19 was flown home from India aboard a special plane, together with his wife and four children.
Doctors said the man had to be evacuated because he was in a serious condition.
India's healthcare system has been overwhelmed as the country grapples with record coronavirus infections and deaths.
India's health ministry on Sunday reported 4,092 deaths over the past 24 hours, taking the overall death toll to 242,362. New cases rose by 403,738, just shy of the record and increasing the total since the start of the pandemic to 22.3 million.
(pk)
Source: PAP/Reuters