The centre's observation tower is Scotland's largest

An estimated 1,000 visitors arrived for the attraction's first day - but could not be charged an entrance fee because of the delay in securing a public entertainment licence.

Members of Glasgow City Council's Licensing (Applications) Sub-Committee spotted the potential flaw on a visit to the site on Wednesday.

Councillors delayed a decision on whether to grant the licence after a committee meeting heard that railings on the upper floors of the building might be wide enough for youngsters to slip through.

The sub-committee is now set to hold a special meeting on Monday, three days before the Queen is due to conduct the centre's royal opening.

Safety issues

A council spokesman said: "The sub-committee will hold a special meeting on Monday to allow further discussions with the Science Centre and council building control services, and also action on safety issues raised by members of the sub-committee."

The Science Mall is the centrepiece attraction of the Glasgow Science Centre and is expected to attract up to 600,000 visitors a year.

Its four floors house hundreds of interactive exhibits made up of light beams, mirrors, optical illusions, audio and computer displays, and water tanks.

The mall and the adjacent Imax theatre, which opened last October, are the first titanium-clad buildings in the UK.