A rapist inflicted "immeasurable damage" on young girls after committing sexual offences against them over a 14-year period has been jailed for six and a half years.

Two of Thomas Shields' victims were just four when he first began targeting them, while a third girl was raped when she was 15 after suffering abuse from him since she was 12.

Shields, 57, of Lenzie Place in Springburn, Glasgow, earlier admitted a total of seven charges including rape, attempted rape and indecency offences. The crimes took place at addresses in the city between 1988 and 2002.

Sentencing Shields at the High Court in Edinburgh on Tuesday, Lady Scott told him: "You have pled guilty to seven charges of the sexual abuse of three young children. This is a very serious, sustained course of sexual abuse. It requires a very substantial prison sentence."

She told Shields he would have faced a 10-year prison term if he had pleaded not guilty. Lady Scott said the young age of the victims and the protracted nature of the offending made it particularly serious.

The judge told Shields: "You have caused immeasurable damage to your victims. They have ongoing difficulties and require professional help."

She said he had robbed the victims of their childhoods and future trust.

Shields showed pornographic material to one victim and carried out sex acts and tried to rape her. Another child was also shown sexual images during the abuse she was subjected to by Shields.

The former ventilation worker’s counsel Euan Dow said Shields was willing to take part in any programmes in jail. Mr Dow said his client was assessed as having a low risk of further offending.

He said: "He does not have any previous convictions but clearly that has to be seen in the light of the extensive and lengthy offending that forms the present indictment."