Ukrainian President Volodymyr Zelensky openly invited foreigners to his country to form part of an 'International Legion' that would fight side by side with Ukrainians against the Russians.

Ukrainian President Volodymyr Zelenskiy called on Sunday for the formation of an 'international legion,' prompting dozens from the US and Canada to volunteer.

Sometimes 'disaster tourists' come only to take pictures and fill up their social media pages.

Eager to do what they can, they have enrolled as volunteers at vaccination centres across the country.

Health director-general Dr Noor Hisham Abdullah says volunteers are needed to ease the burden of ministry healthcare personnel nationwide.

The researchers would use the results to study how vaccines might work and to explore potential treatments.