* UN Human Rights Council sets up year-long investigation
* Says rights abuses may amount to crimes against humanity
* North Korea denies abuses, says accusations "political" (adds quotes, background)
By Stephanie Nebehay
GENEVA, March 21 The United Nations launched an investigation on Thursday into what it said were widespread and systematic human rights violations in North Korea, some of which "may amount to crimes against humanity".
The U.N. Human Rights Council unanimously passed a resolution brought by the European Union and Japan, and backed by the United States, condemning alleged North Korean torture, food deprivation and labour camps for political prisoners.
The 47-member forum set up a three-member commission of inquiry for one year and called on Pyongyang to cooperate with the team of experts, including Marzuki Darusman, its special rapporteur on the Democratic People's Republic of Korea (DPRK).
"The creation of the commission of inquiry sends an important message that the global community is paying close attention to the situation in the DPRK, not just on the nuclear front, but also especially on the human rights front," U.S. Ambassador Eileen Chamberlain Donahoe told reporters in Geneva.
The investigation will "help focus the spotlight of sustained international scrutiny on one of the world's darkest and most secretive regimes", she said.
Navi Pillay, U.N. High Commissioner for Human Rights, called in January for an international investigation into what she said may be crimes against humanity, including torture and executions of political prisoners in North Korean camps.
She said Pyongyang's network of political prison camps is believed to confine at least 200,000 people and has been the scene of rapes, torture, executions and slave labour.
Neither North Korea's closest ally, China, nor Russia are currently members of the Geneva forum, and thus have no vote.
More U.N. sanctions were imposed on Pyongyang this month in response to its third nuclear test on Feb. 12, including tougher financial penalties to try to curb its nuclear arms programme.
During the Human Rights Council debate, North Korean Ambassador So Se Pyong rejected the resolution as "an instrument that serves the political purposes of the hostile forces in their attempt to discredit the image of the DPRK".
"As we stated time and again, those human rights abuses mentioned in the resolution do not exist in our country," So said, warning that the sponsors should be held accountable "for all serious consequences".
North Korea said earlier on Thursday it would attack U.S. military bases in Japan and on the Pacific island of Guam if provoked, a day after leader Kim Jong-un presided over a mock drone strike on U.S.-allied South Korea.
Irish Ambassador Gerard Corr, speaking on behalf of the EU, said the commission of inquiry would work "with a view to ensuring full accountability, in particular where these violations may amount to crimes against humanity".
"The EU and Japan have not taken such a step lightly," Corr said. He added that North Korea had not heeded the Council's calls over the years to improve the situation and cooperate.
Japan's envoy, Takashi Okada, denounced disappearances in North Korea, including the abduction of foreign nationals.
Activists welcomed the establishment of a U.N. inquiry similar to the one on Syria, which aims to document war crimes committed by both sides in a civil war to build a case for future prosecution.
"This long-awaited inquiry will help expose decades of abuse by the North Korean government," Julie de Rivero, advocacy director at Human Rights Watch, said in a statement.
Rajiv Narayan, North Korea Researcher for Amnesty International, said: "U.N. member states have today sent a clear message to the North Korean authorities that those responsible for crimes against humanity will ultimately be held to account.
"Millions of people in North Korea suffer extreme forms of repression. Hundreds of thousands, including children, remain in political prison camps and other forms of detention where forced hard labour, torture and other ill treatment is systemic."
(Editing by Mark Heinrich)