Rusma bipakshi netako hatya-

Western leaders have called on the Russian authorities to get to the truth behind the killing of opposition politician Boris Nemtsov. The US president urged a "transparent investigation". The German chancellor said the killing must be explained and the perpetrators brought to justice. Mr Nemtsov was shot four times in the back on a bridge near the Kremlin. President Putin quickly condemned the killing and has taken personal control of the investigation. Investigators say the murder may have been aimed at "destabilising" Russia. Russian investigative committee head Vladimir Markin said in a statement that several motives for the killing were being considered including "Islamic extremism" and the victim's alleged links with Ukraine. It added that the attack was meticulously planned and the killers - who fled in a car - had been tracking Mr Nemtsov's movements around the city. Boris Nemtsov died hours after appealing for support for a march on Sunday in Moscow against the war in Ukraine. Amid widespread global outrage, US President Barack Obama condemned the killing of Mr Nemtsov as a "brutal murder". Independent experts echo that accusation while Moscow denies it, insisting that any Russians serving with the rebels are "volunteers".