The prize is a huge victory for small Tunisia, whose young and still shaky democracy suffered two extremist attacks this year that killed 60 people and devastated the tourism industry.

The National Dialogue Quartet is made up of four key organizations in Tunisian civil society: the Tunisian General Labour Union; the Tunisian Confederation of Industry, Trade and Handicrafts; the Tunisian Human Rights League; and the Tunisian Order of Lawyers.

"The Nobel Peace Prize for 2015 is awarded to this Quartet, not to the four individual organizations as such," the committee said.

There were 273 candidates nominated for the 2015 peace prize, five fewer than in 2014.

The award capped a week of Nobel Prize announcements, with the winners of the medicine, physics, chemistry and literature awards presented earlier in Stockholm.

The economics award - not an original Nobel Prize but created in 1968 - will be announced on Monday.

(AP)