The explosion tore through a restaurant attached to a mall in Doha, Qatar Television said. It was not immediately clear whether the blast was accidental.
Footage showed paramedics carrying a covered body past rubble strewn some 50 metres away from the building, whose roof had caved in.
Pictures posted on Twitter showed several damaged cars.
A witness said police had cordoned off the area.
In May 2012, 19 people were killed in a blaze at a major Doha mall, including 13 children and four supervisors at a nursery located within the shopping centre.