text: This year's award was won jointly by Ellen Johnson Sirleaf, the president of Liberia, Leymah Gbowee, the Liberian peace activist, and Yemeni pro-democracy campaigner Tawakkol Karman.
  They were recognised for their "non-violent struggle" for women's safety and for women's rights to participate in peace-building work.
  Chinese lawyer Liu Xiaobo won in 2010.
  Each of this year's winners was presented with a gold medal and a diploma.
  The prize money of $1.5 million (Â£958,000) will be shared between them.
  Mrs Sirleaf, 72, is Africa's first elected female head of state and is credited with helping to end Liberia's 14 year civil war. The announcement of her award came days before the country's presidential election.
  She went on to win a run-off poll last month but her rival boycotted the vote alleging the first round was rigged.
  The Liberian president told delegates that she was honoured to be following in the footsteps of the Africans who had won the prize before her, including South Africa's Archbishop Desmond Tutu and Kofi Annan, the Ghana-born former UN secretary-general.
  Mrs Sirleaf also expressed her "deepest sympathy" for the people of Norway in the wake of the twin attacks carried out by Anders Behring Breivik on 22 July that led to the deaths of 77 people.
  "On behalf of all the women of Liberia, the women of Africa, and women everywhere in the world who have struggled for peace, justice and equality, I accept with humility the 2011 Nobel Prize for Peace," she said.
  Ms Gbowee, 39, led a peaceful campaign to end Liberia's civil war and oust its ex-President Charles Taylor.
  She said: "I am humbled and honoured to have been selected and I receive the prize in the name of women who continue to work for peace, equality and justice across the world."
  "I believe that the prize this year not only recognises our struggle in Liberia and Yemen.
  "It is in recognition and honour of the struggles of grass roots women in Egypt, the Democratic Republic of Congo, Cote d'Ivoire [Ivory Coast], Tunisia, in Palestine and Israel, and in every troubled corner of the world."
  Ms Karman, a 32-year-old mother of three, founded the organisation Women Journalists Without Chains in 2005 and becomes the first Arab woman to win the prize.
  'Freedom and dignity'
  Addressing the audience in Arabic, she said: "Thank you for the award, which I consider as an honour to me personally, to my country Yemen, to Arab women, to all women of the world, and to all people aspiring to freedom and dignity.
  Recent Nobel Peace Prize winners
  "I accept the award on my behalf and on behalf of the Yemeni and Arab revolutionary youth, who are leading today's peaceful struggle against tyranny and corruption with moral courage and political wisdom."
  Speaking before the presentation at Oslo's City Hall, Thorbjorn Jagland, the chairman of the Norwegian Nobel Committee, said: "We congratulate this year's winners of the Nobel Peace Prize.
  "You represent one of the most important motive forces for change in today's world, the struggle for human rights in general and the struggle of women for equality and peace in particular."
  The Nobel committee received a record 241 nominations for the 2011 prize.
  The first Nobel peace prize was awarded in 1901 and the award takes its name from the Swedish scientist Alfred Nobel.
target: The 2011 Nobel Peace Prize has been presented to three women at a ceremony in the Norwegian capital, Oslo.