World

Mourners line up to view body of slain Russian opposition leader Boris Nemtsov

  • Relatives and friends pay their last respects while passing the coffin of Boris Nemtsov, a charismatic Russian opposition leader and sharp critic of President Vladimir Putin, during a farewell ceremony inside the Sakhavov's center in Moscow, Russia, Tuesday, March 3, 2015. Mourners are lining up outside the Moscow human rights center for the funeral of murdered Nemtsov. Western officials have called for Russia to conduct a prompt, thorough, transparent and credible investigation into the slaying. Putin has ordered law enforcement chiefs to personally oversee the probe. (AP Photo/Pavel Golovkin)

    Relatives and friends pay their last respects while passing the coffin of Boris Nemtsov, a charismatic Russian opposition leader and sharp critic of President Vladimir Putin, during a farewell ceremony inside the Sakhavov's center in Moscow, Russia, Tuesday, March 3, 2015. Mourners are lining up outside the Moscow human rights center for the funeral of murdered Nemtsov. Western officials have called for Russia to conduct a prompt, thorough, transparent and credible investigation into the slaying. Putin has ordered law enforcement chiefs to personally oversee the probe. (AP Photo/Pavel Golovkin)  (The Associated Press)

  • Relatives and friends pay their last respects while passing the coffin of Boris Nemtsov, a charismatic Russian opposition leader and sharp critic of President Vladimir Putin, during a farewell ceremony inside the Sakhavov's center in Moscow, Russia, Tuesday, March 3, 2015. Mourners are lining up outside the Moscow human rights center for the funeral of murdered Nemtsov. Western officials have called for Russia to conduct a prompt, thorough, transparent and credible investigation into the slaying. Putin has ordered law enforcement chiefs to personally oversee the probe. (AP Photo/Pavel Golovkin)

    Relatives and friends pay their last respects while passing the coffin of Boris Nemtsov, a charismatic Russian opposition leader and sharp critic of President Vladimir Putin, during a farewell ceremony inside the Sakhavov's center in Moscow, Russia, Tuesday, March 3, 2015. Mourners are lining up outside the Moscow human rights center for the funeral of murdered Nemtsov. Western officials have called for Russia to conduct a prompt, thorough, transparent and credible investigation into the slaying. Putin has ordered law enforcement chiefs to personally oversee the probe. (AP Photo/Pavel Golovkin)  (The Associated Press)

  • Relatives and friends pay their last respects while passing the coffin of Boris Nemtsov, a charismatic Russian opposition leader and sharp critic of President Vladimir Putin, during a farewell ceremony inside the Sakhavov's center in Moscow, Russia, Tuesday, March 3, 2015. Mourners are lining up outside the Moscow human rights center for the funeral of murdered Nemtsov. Western officials have called for Russia to conduct a prompt, thorough, transparent and credible investigation into the slaying. Putin has ordered law enforcement chiefs to personally oversee the probe. (AP Photo/Pavel Golovkin)

    Relatives and friends pay their last respects while passing the coffin of Boris Nemtsov, a charismatic Russian opposition leader and sharp critic of President Vladimir Putin, during a farewell ceremony inside the Sakhavov's center in Moscow, Russia, Tuesday, March 3, 2015. Mourners are lining up outside the Moscow human rights center for the funeral of murdered Nemtsov. Western officials have called for Russia to conduct a prompt, thorough, transparent and credible investigation into the slaying. Putin has ordered law enforcement chiefs to personally oversee the probe. (AP Photo/Pavel Golovkin)  (The Associated Press)

Mourners are lining up outside a Moscow human rights center for the funeral of slain opposition leader Boris Nemtsov.

Nemtsov was shot to death late Friday while walking on a bridge near the Kremlin with a companion. No suspects have been arrested.

The killing has deeply shaken Russia's small and marginalized opposition movement. Many opposition supporters suspect the killing was ordered by the Kremlin in retaliation for his ardent criticism of President Vladimir Putin, while authorities have suggested several possible motives including a provocation aimed at tarnishing Putin's image.

Nemtsov's body on Tuesday lay in a coffin lined in white fabric in the Sakharov Center in central Moscow. The center is named after the late Soviet-era dissident and Nobel Peace Prize laureate Andrei Sakharov.