One person has been killed after jumping to safety after the blaze broke out at the Centara Grand hotel and Centralworld shopping plaza.
Thick black smoke can be seen billowing from the roof of the convention centre, which is the eleventh biggest in the world.
The 57-floor Centara Grand is the Central Group’s flagship hotel and one of the biggest hotels in Thailand’s capital.
The fire broke out between 5pm and 6pm local time (11am and 12pm BST).
Traffic is gridlocked around the centre as emergency services try to get to the area during rush hour.
Rajdamri Road had come to a standstill as hundreds of people stand outside after being evacuated from Centralworld soon after 6pm.
One witness said on Twitter: “Run away from the dreaded Central World, the 7th floor of the fire is very thick smoke, but there are no alarms.
“Now I’m worried about the people in the cinema because there is no announcement yet.”
Unconfirmed reporters from the nearby Erawan shopping centre said one person had died and two people were injured.
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