Two Finnish female aid workers were shot dead by unknown gunmen while traveling in a taxi in western Afghanistan on Thursday, officials said, the latest killings in a recent spate of attacks on foreigners.

It came as Afghanistan undertakes a massive audit of its recently concluded presidential vote to avert an impasse threatening to plunge the country into an ethnic conflict as foreign troops prepare to depart after more than a decade of war.

Europe's top human rights court condemned Poland on Thursday for hosting secret CIA prisons on its territory, saying Warsaw knowingly abetted unlawful imprisonment and torture of Guantanamo-bound detainees.

Norway has taken exceptional security measures after being informed of a possible imminent "terrorist attack" by militants who have fought in Syria, the country's intelligence chief said Thursday.

A suicide bomber detonated an explosive-packed motorcycle in northern Afghanistan Thursday, killing six civilians and wounding more than 20 in a crowded market as shoppers bought supplies for the upcoming festival of Eid-ul-Fitr, officials said.

The attack in Takhar province came as Afghanistan is conducting an audit of its presidential vote aimed at ending an impasse that has threatened to plunge the country into a crisis as foreign troops prepare to withdraw by the end of the year.

Church properties have been bulldozed and seized in a climate of growing harassment of minority Christians in Islamist-run Sudan since the south's 2011 independence, its council of churches said.

Kori Elramla Kori Kuku, general secretary of the Sudan Council of Churches, told AFP that harassment has been on the rise ever since the separation three years ago of South Sudan, whose population follow mainly Christian and traditional beliefs.

A senior Russian official called Thursday on the United States to prove its claims that the Malaysian passenger airliner shot down last week was hit by a missile fired from rebel-held territory in Ukraine.

"They've said U.S. intelligence has technical data and satellite photos which show that the missile was launched from rebel-held territory. The question is where is this data", Deputy Defense Minister Anatoly Antonov said in an interview with Russia-24 television.

South Sudan's warring leaders will resume peace talks by the end of the month, mediators said Thursday, as warnings grow of famine within weeks if fighting continues.

Peace talks between President Salva Kiir and his former deputy Riek Machar stalled last month with each side blaming the other for the failure.

A passenger train rammed into a school bus in southern India on Thursday, killing at least 11 children, with fears the death toll could be as high as 25, officials said.

The train collided with the bus carrying some 38 children to school in the southern state of Telangana, dragging the mangled vehicle several hundred meters down the tracks, local media reports said.

U.S. authorities can place Americans and foreigners on a terrorist watch list indefinitely on the basis of vague rules without concrete evidence, according to a government document leaked Wednesday.

Once blacklisted, individuals have no way of finding out why they are deemed suspicious and even dead people's names remain on the list, under secret guidelines set out last year by the National Counter-Terrorism Center (NCTC), which were published for the first time by The Intercept news website.

Several thousands held a fresh protest in Paris on Wednesday against the Israeli offensive in Gaza amid tight security days after similar rallies descended into violence and looting.