KYIV - Powerful explosions were heard in Kyiv early on Tuesday, Reuters witnesses and local media reported, with Ukraine's air defence forces saying all of the country was under the threat of a Russian ballistic weapons attack.

It was not clear whether the explosions were air defence systems in operation or air weapons hitting their targets.

"Don't ignore the air raid alerts, seek cover," Ukraine's air force said on the Telegram messaging app.

  - Reuters