Three women won the 2011 Nobel peace prize

They were recognised for their "non-violent struggle for the safety of women and for women's rights to full participation in peace-building work".
Mrs Sirleaf is Africa's first female elected head of state, Ms Gbowee is a Liberian peace activist and Ms Karman is a leading figure in Yemen's pro-democracy movement.

"We cannot achieve democracy and lasting peace in the world unless women achieve the same opportunities as men to influence developments at all levels of society," said Nobel Committee chairman Thorbjorn Jagland in Oslo.

Reading from the prize citation£¨ÒýÓã© , he said the committee hoped the prize would "help to bring an end to the suppression of women that still occurs in many countries, and to realise the great potential for democracy and peace that women can represent".

German Chancellor Angela Merkel - deemed by Forbes the world's most powerful woman - called the award a "wise decision".

But Mrs Sirleaf's main rival in polls this coming Tuesday, Winston Tubman, told the BBC she did not deserve the prize and was a "warmonger£¨ºÃÕ½Õߣ© ".

Arab Spring

Mrs Karman heard of her win from protest camp Change Square in the capital Sanaa, where she has been living for several months calling for President Ali Abdullah Saleh to stand down.

She was recognised for playing a leading part in the struggle for women's rights in Yemen's pro-democracy protests "in the most trying circumstances" and is the first Arab woman to win the prize.

As the head of Yemeni organisation Women Journalists without Chains, Mrs Karman has been jailed several times.

Mrs Karman told BBC Arabic she was dedicating it to "all the martyrs£¨ÁÒÊ¿£© and wounded of the Arab Spring" - the wave of unrest which has swept the Middle East and North Africa in the past year - and to "all the free people who are fighting for their rights".

Mr Jagland said the oppression of women was "the most important issue" in the Arab world and that awarding the prize to Ms Karman was "giving the signal that if it [the Arab Spring] is to succeed with efforts to make democracy, it has to include women".