Part of a Glasgow train line is to remain closed until next week after a sinkhole swallowed a section of the track.

Network Rail has said the line between Airdrie and Bathgate is expected to remain shut until Monday, April 29, due to the 'potentially complex nature of the repairs needed' to the railway.

It comes after we first reported about the issue on Sunday, April 21.

The sinkhole is between Caldercruix and Drumgelloch.

READ MORE: Glasgow train services disrupted after sinkhole swallows track

Now, the rail firm and its contractors are working to establish the sinkhole's size and depth, and the presence of an underground spring is being looked at as a potential cause.

Once investigations are complete, engineers will then be able to put together a repair plan, as well as give a clearer indication of when the line can reopen.

In the meantime, ScotRail services between Helensburgh Central and Edinburgh will terminate at Airdrie.

A replacement bus service will then connect Airdrie and Bathgate, calling at all intermediate stations in between, with a train shuttle service then running between Bathgate and Edinburgh.

Meanwhile, trains between Balloch and Airdrie are not affected.

Network Rail has previously shared pictures of the sinkhole on social media.

In the images, a large hole can be seen under the tracks.

READ MORE: Glasgow trains face further disruption after sinkhole swallows track

Ross Moran, Interim Route Director for Network Rail Scotland, said: “Sinkholes like this are very unusual on the railway, and our specialist geotechnical engineers are working tirelessly to identify the cause, as well as planning the repairs, so we can reopen the railway. 

“We understand the inconvenience this incident will cause for passengers, and I’d like to thank those who travel on this route for their patience and understanding while work continues.”

Phil Campbell, ScotRail Customer Operations Director, said: “We are doing everything we can to keep our customers moving while this issue is resolved, with replacement buses between Airdrie and Bathgate.

“Customers should plan their journey in advance and allow some extra time, as the bus service will take longer.”