Hundreds of mourners have gathered at a memorial service for the 11 victims who died in a head-on train crash in southern Germany.

Lutheran Bishop Susanne Breit-Kessler told families and friends of the dead on Sunday that "we want to carry together the unbearable," the German news agency dpa reported.

The joint Lutheran and Catholic service took place in a church in Bad Aibling, 60 kilometers (40 miles) southeast of Munich, where the two trains slammed into each other on a single-line track on Tuesday, killing 11 and injuring dozens of others.

Rescue personnel have spent the last few days removing the trains' wreckage, and authorities are still trying to determine why the crash happened.

Investigators are considering possible technical errors, human failure or a combination of the two scenarios.