Remembering the victims of a tragedy.

A church service is held in Belgium for 28 people who died during a bus crash in Switzerland last week.

Church leaders described the accident - which killed 22 children - as a nightmare.

(SOUNDBITE) (Dutch) MONSIGNOR LEMMENS, SAYING:

"In the morning we woke up to the news that overwhelmed us like a deep black nightmare. The parents, brothers and sisters from families, friends and neighbours, not only

people in our country but countless persons in Europe and the whole world are shocked by this tragedy."

Many of the victims were from this school in Belgian town of Heverlee.

Mourners here have created a makeshift memorial - part of a national outpouring of grief.

The children were on a ski trip in the Swiss Alps when the bus they were riding in careened into the wall of a tunnel.

Swiss police are still investigating the cause of the crash.

Andrew Raven, Reuters