Britain warns Putin over chemical weapons as Ukraine raises alarm on Chernobyl

A shelter covers the exploded reactor at the Chernobyl nuclear plant (Efrem Lukatsky/AP)

Britain has warned Vladimir Putin of a “dramatic increased response” from the West if he uses chemical weapons in Ukraine, amid warnings over a possible attack on Chernobyl.

Ukrainian defence intelligence alleged on Friday that the Russian president is “preparing a terrorist attack” on the facility seized by Moscow’s troops.