• Ukraine's nuclear regulator says a fire broke out at a building on the site of the country’s biggest nuclear power plant after shelling by Russian forces
• IAEA says the fire, extinguished at 06:20 local time (04:20 GMT), had not affected ‘essential’ equipment
• The six power units at Zaporozhe 'remain intact' and no changes in radiation levels registered
• Regulator says the site is occupied by Russian forces
• IAEA director general appeals for halt to use of force, plans to travel to Ukraine