Christian leaders have been speaking of their sorrow over Tuesday's triple bombing attack on Belgium.

Two bombs went off at Brussels' Zaventum airport at 08:00 local time and another on a metro train at around 09:11, killing at least 34 people.  The airport has been closed and the city has gone into lockdown following the explosions.  ISIS has claimed responsibility for the attacks, which come just days after the arrest of Paris terror attack suspect Salah Abdeslam in Brussels.

Belgian Prime Minister Charles Michel described the attacks as a "black moment" for his country while French President Francois Hollande responded with a statement in which he spoke of a "global threat which necessitates a global response".

Flags are flying at half mast at the European Commission, close to where the explosion occurred on the metro train.

Christian leaders have shared in the horror over this latest terrorist attack to hit the European continent.  The Archbishop of Canterbury Justin Welby was among those offering condolences on Twitter.

"Deeply shocked by cruel attacks in Brussels. This Holy Week let us pray for the victims, for peace and for true service to our loving God," he tweeted.

Other Christian leaders have expressed their solidarity with the people of Belgium.