Police in Turkey's capital have used tear gas and water cannon to push back hundreds of activists trying to reach Ankara's main train station to commemorate more than a hundred victims of an attack blamed on Islamic State militants.

Authorities, citing security concerns, banned large-scale commemorations that were scheduled for Monday to mark the first anniversary of the twin suicide bombings that targeted peace activists gathering for a rally in front of the station. The attack was the deadliest in Turkey.

Police blocked roads leading to the station and barred demonstrators from marching to the station, chasing some of them down a main street.

However, authorities allowed families of the victims and some representatives of civil society groups to lay carnations at the spot.