A bomb has exploded in a hijacked bus left outside a west Belfast police station, as army experts tried to defuse it.

The device, containing an estimated 5kg of explosives, went off on the bus on Stewartstown Road near the gates of the Woodbourne base.

There were no injuries reported, and damage was restricted to the gates and the bus.

A number of houses on the Stewartstown Road had already been evacuated, after the bus was hijacked earlier in the day.

Two armed and masked men ordered the sole passenger off, placed the device on board and ordered the driver to drive to the police station.

On arrival the men fled and the driver raised the alarm.

An army bomb disposal team carried out a number of controlled explosions on the device to try to defuse it, but during the operation it exploded.

Superintendent Maggie Hunter said it was a "reckless terrorist act in which people could have died or been injured."