Two of the six iconic Red Road towers remained partially standing due to an unforeseen difficulty.

The top half of two of the buildings remained standing at a slight angle after the bottom halves were destroyed.

The delay meant that many of the 2,500 residents evacuated for the demolition returned home around an hour later than previously scheduled.

Glasgow Housing Association (GHA) apologised for the delay and said it will begin a review with the demolition company to decide what to do over the next few days.

A GHA spokesman said: “The original plan for today’s demolition was that 10 floors of the blocks would remain for dismantling, post blowdown, by machine. However, this did not go completely to plan with two of the six blocks. Over the next few days the contractors, Safedem, will carry out a review to determine the best way of now completing the demolition.

“Residents began moving back into their homes shortly after 6pm, just over an hour later than originally planned.

“We sincerely apologise to everyone involved for this delay and any additional inconvenience caused.”

The decision to bring all six blocks down in a single blowdown was taken following feedback from local residents and was intended to be less disruptive to residents and businesses than carrying out multiple evacuations.

A plan to blow up five of the remaining blocks during the Opening Ceremony of the Glasgow 2014 Commonwealth Games was scrapped last year.

The demolition is the latest part of GHA’s regeneration of communities across the city which will see thousands of new homes built.

The planned schedule remains for all eight blocks to be demolished and the site cleared by 2017.

Future development options for the cleared site are at an early stage and will include further community consultation over the summer.