Bosses have promised Glasgow's Subway system will fully reopen by tomorrow.

But, following days of delays, passengers are demanding answers as Cowcaddens station stayed shut four days after a tunnel fault sparked safety fears.

Cowcaddens and Buchanan Street stations were both closed by the problem, but Buchanan Street has since reopened.

However, passengers are furious as Subway bosses failed to give updated details about repair timescales.

An SPT spokeswoman said Cowcaddens would reopen on Saturday "at the latest".

But at St George's Cross station one passenger, who asked not to be named, said: "The delays are ridiculous.

"If we had any idea what was going on then we might be more sympathetic.

"If there is a fault in the tunnel then they should be saying exactly what is wrong and how long it will take to fix.

"Instead we have been going day to day altering our journeys."

Travellers using the system, which carries 40,000 people each day, are still not able to get on or off at Cowcaddens on the inner circle.

Restrictions are also in place on the outer circle, with a limited service running from Govan to St George's Cross.

Shuttle buses were in place from St George's Cross station to Buchanan Street, stopping at Cowcaddens, and from Buchanan Street to Shields Road via Bridge Street.

The problem with the tunnel wall was found during checks on Monday.

The SPT spokeswoman said structural engineers were in their final phases of tunnel safety checks.

SPT said the inner circle would be operating a frequent service.

It added: "Cowcaddens station remains closed.

"The inner circle is in operation, stopping at all stations apart from Cowcaddens.

"A reduced service is running on the outer circle from Govan to St George's Cross."

A free shuttle bus service was in place from St George's Cross to Buchanan Street via Cowcaddens until 11.30pm last night.

A shuttle bus service was also in operation from Buchanan Street to Shields Road via Bridge Street station until 7pm.

These buses will remain in service today.

Earlier in the week a shuttle train was running from West Street to Ibrox but this was stopped yesterday.

Subway bosses advised passengers to use the inner circle instead.

SPT said trains on the outer circle would not stop at Bridge Street, St Enoch and Buchanan Street because it would put too much pressure on the transport system.

A £1.3million programme to improve the Subway's tunnels has been under way since last year.

The system is also undergoing a £300m renovation project, which will include driverless trains.

catriona.stewart@eveningtimes.co.uk

What travellers think of the disruption ...

Sophia Platts-Palmer, Student, 22, St George's Cross

"I have a new job so was trying to be early and had to try and find a bus to take instead.

"It would be better if SPT gave out more information about how long the Subway is going to be closed and what the problem is.

"It should utilise Facebook and Twitter to give people an idea of how long repairs will take."

Graham Morton, Engineer, 28, St George's Cross

"The delays have had a huge impact on my travel to work in Govan. One day my commute took a full hour.

"It has been getting better as the week has gone on, but it would be nice to be told how long the delays will last. It is extremely frustrating not knowing what is happening from day to day."

Heather Forbes, Gaelic development officer, 31, St George's Cross

"I had to walk into the city centre to get to work, which was a pain in the neck.

"Enough information was given out initially on the radio and online, but since then it has not been made clear exactly what is wrong with the tunnel and how long it's going to be closed for. Passengers really need to know."

Robert Flaherty, Radiographer, 25, city centre

"I do not use the Subway for getting to work, but I do for socialising and the problems have been a nightmare.

"Unless you want to be late it is a case of taking taxis or buses everywhere because you just don't know what is happening.

"They need to be clearer about how long this is going to take."