Traffic has returned to normal following a series of collisions on the M7 and M9 in Co Kildare this morning.

At least 27 people were injured in the of multiple car pile-ups, involving up to 100 cars.

One person is in a critical condition in Naas General Hospital after the incident, which delayed motorists for up to four hours.

Two people are described as being in a serious condition, with at least 24 others receiving minor injuries.

A major emergency plan swung into action amid heavy fog in the area, with over 23 ambulances from neighbouring counties attended the scenes of the crashes.

The first major crash happened on the M7 just north of the Newhall junction. Shortly after, a car and a truck collided 2km further south.

There were up to 40 other minor collisions along the 3km stretch of the M7 up to the Curragh junction.

And there were another 40 crashes on the M9, just south of the junction with the M7.

A helpline for people wondering about relatives has been set up on 045-849514 or 045-849521.

Both the M9 and the M7 northbound have now fully reopened to traffic.