It's thought the attack could last several days.
MSPs to quiz Justice Secretary on Police Scotland budget gap forecast
Justice Secretary Michael Matheson is to be questioned over a forecast £27.5 million budget gap facing Police Scotland at Holyrood on Thursday.
Mr Matheson is also expected to face questions about a senior police officer's claim the force needs an extra #80 million to deliver a service up to standard.
Chief Superintendent Gordon Crossan, of the Association of Chief Scottish Police Superintendents, previously told MSPs he lacked confidence that "we can continue to deliver a police service'' without the £80 million funding boost.
Labour MSP Mary Fee, convener of the Justice Sub-Committee on Policing, said the committee would question Mr Matheson on "how he intends to ensure that the police service has the resources to continue as the 'service of first response and last resort''' at its meeting.
Last month's committee took evidence on the police budget from police staff organisations and policing authorities, and heard claims the Scottish Police Authority (SPA) was ``excluding'' staff associations from financial talks, which Ms Fee said was "disappointing''.
SPA chairman Andrew Flanagan told the previous committee 90% of the costs went on staff and ``cost pressures'' facing the force include the Scottish Government policy not to let police officer numbers drop below 17,234.
Ms Fee said: "We heard concerns during the first session we held on the police budget from both those at the operational and managerial levels of policing in Scotland.
"Although there was no clear consensus from our panel, there was agreement that there are significant cost pressures on Police Scotland.
"We will be asking the Cabinet Secretary how he intends to ensure that the police service has the resources to continue as the 'service of first response and last resort', and the actions he will take to address the issues we heard about, and to influence positive changes to Policing Scotland.''
Sturgeon says Trump is on the "wrong side" of the debate.
The boys were found inside the Sainsbury's store at 2am on Tuesday.
The incident, which happened at Ibrox station, was reported to British Transport Police before 8pm on Saturday.
Most Viewed Pictures On Heart
Recently Played Tracks
To listen live, choose your preferred station:
Now playing: The best feel good music
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart Scotland- East.