The third explosion in the Turkish town of Reyhanli, close to the Syrian border, appears to have been a smaller blast caused by a car engine or a building boiler room, local reporters have told Reuters.
It followed two car bombs that exploded in the early afternoon in the city and killed around 40 people.
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Cloud and outbreaks of rain will ease away eastwards during the morning, clearing the east coast around midday with sunny spells developing.
Police and emergency services are attending the scene.
Rebel-held east remains at risk while the pumping station supplying the western part of the city is once again in operation.