Thirteen persons were injured when the driver of an underground train in Milan had to brake hard to avoid hitting a woman who had walked into a tunnel.

The incident took place this morning at the Loreto stop on Line 1.

The woman, aged 32, was caught on camera walking on the edge of the platform and, after stopping for a few seconds, walked into the tunnel as a train was approaching.

Her action sparked the activation of a security alert which informed the driver of the impending danger, but the sudden braking of the train led to people inside the carriages being injured.

Italian media said that 13 needed treatment.

The woman, who appeared unaware of what she had just caused, was taken to hospital.