Fourth explosion has struck the Brussels Metro, a correspondent of i24news reports.
Three previous explosions ripped through Maelbeek and Schuman metro stations.
A blast at the Maalbeek metro station in Brussels has killed at least 15 people according to local police, as cited by RTBF television, RT reports.
According to most recent reports, the death toll from Brussels attacks on March 22 has climbed to 28 and is likely to grow further. Earlier, it was reported about 21 victims.
Smoke is seen coming out of the attack metro stations in Brussels. All metro stations in the city have been closed.
Update: The death toll from Brussels bombings has climbed to 31.