KYIV (REUTERS) - Russia's invasion of Ukraine has devastated hundreds of hospitals and other institutions and left doctors without drugs to tackle cancer or the ability to perform surgery, President Volodymyr Zelensky said on Thursday (May 5).

Zelensky, in a video address to a medical charity group, said many places lacked even basic antibiotics in eastern and southern Ukraine, the focal points of the fighting.

"If you consider just medical infrastructure, as of today Russian troops have destroyed or damaged nearly 400 healthcare institutions: hospitals, maternity wards, outpatient clinics," he told the gathering.

In areas occupied by Russian forces, he said, the situation was catastrophic.

"This amounts to a complete lack of medication for cancer patients. It means extreme difficulties or a complete lack of insulin for diabetes. It is impossible to carry out surgery. It even means, quite simply, a lack of antibiotics."

The Kremlin says it targets only military or strategic sites.

In one of the most widely denounced acts of the war, a maternity hospital was all but destroyed on March 9 in the city of Mariupol.

Russia alleged pictures of the attack were staged and said the site had been used by armed Ukrainian groups.