Ukrainian drones struck an oil terminal and naval base in St Petersburg hours before President Vladimir Putin's showcase economic forum got under way, an attempt to embarrass the Kremlin chief and show how vulnerable Russia's cities are.

The bus was travelling between Moscow and Simferopol, in Russian-occupied Crimea, an official says.

The Leningrad region is hosting the “Russian Davos” economic conference in St Petersburg from June 3. Read more at straitstimes.com. Read more at straitstimes.com.

A drone strike in Donetsk kills seven and wounds eleven, prompting a criminal investigation into a suspected terrorist attack.