Emergency services at the scene of the explosion
At least 50 people have been injured in Belarus after a bomb exploded during a concert in the capital, Minsk.
The event was taking place in the centre of the city to mark the ex-Soviet nation's independence day.
President Alexander Lukashenko, whose rule has been denounced as autocratic by the US and the European Union, was attending the concert.
Police later found an unexploded device in Minsk, Russia's Interfax news agency quoted the interior ministry as saying.
There is no clear motive for the attack, but police say it may have been an act of "hooliganism".
The explosion happened just after midnight local time (2100 GMT), as thousands of people were gathered for a concert at a war memorial in the capital.
Dmitry Kudyakov, 32, said he felt a strong shockwave and saw smoke. "People started crying. Some fell on me and there was a lot of blood," he told the Associated Press news agency.
Screws and bolts have been found at the scene, leading officials to speculate that the device was a home-made bomb.
Most of the injured suffered from shrapnel wounds caused when the bomb exploded.
In the aftermath of the blast, Mr Lukashenko reacted by going over to inspect the scene, his spokesman told Reuters news agency.
"The president was not far. He reached the site of the explosion within several minutes. He did not stay long so as not to interfere with the work of the emergency services," said Pavel Legkiy.
He said the president had not been the target of the attack.
Correspondents say that attacks of this kind are unprecedented in Belarus, which is tightly controlled by Mr Lukashenko.
Belarus became independent when the Soviet Union broke up in 1991.
But the BBC's James Rodgers in Moscow says the president has retained many of the characteristics of Soviet rule.
The West has strongly criticised Mr Lukashenko for his treatment of political opponents.
His supporters credit him with protecting Belarus from the instability which many other former Soviet republics suffered in the 1990s.