Two held hostage in Scottish prison siege
Two members of staff are being held hostage at Saughton Prison in Edinburgh.
The Scottish Prison Service said two members of the nursing staff are being held against their will.
The situation at the prison means a drugs awareness day which was due to take place this afternoon has been cancelled.
A spokesman for the SPS said the prisoner involved in the hostage taking was serving a life term.
He said: "I can confirm that there is an incident ongoing at the prison which started at around eight this morning.
"It involved two members of staff, nursing staff - one male, one female and a prisoner who is serving a life sentence.
"We have dialogue and hostage negotiations to resolve the situation and we are maintaining the usual visits by agents and families to other prisoners in the afternoon."
He added that relatives of the two staff taken hostage are being kept informed of developments.
The latest hostage-taking incident at a Scottish prison comes just over a week after a prison officer was held hostage for around 20 hours by two inmates.
The warder, who was taken prisoner at Craiginches jail in Aberdeen, was eventually freed unharmed after a day of negotiations.
Saughton Prison serves courts in Lothian and Borders and Fife and holds an average of 640 male prisoners.
They include adults and young offenders on remand and convicted prisoners serving up to four years.
A new purpose-designed Visitors Centre was completed at the prison last March.