Pierre Meys, spokesman for the Brussels fire brigade, told AFP that 11 people died in twin blasts at Brussels airport.
There were also "around 10 killed at the Maalbeek metro station where there was an enormous explosion," he said.
"Most of the wounded have been evacuated. The scene is rather chaotic," he said.
The toll at the airport was "initial," he said.
"A false ceiling collapsed with lots of rubble and so there could still be more victims," Meys added.