Kyrgyz President Almazbek Atambayev assailed Belarus on Thursday for sheltering members of the Central Asian republic's former ruling family, following the reported murder of a prominent gangland figure in Minsk earlier this month.

Atambayev claimed the February 18 discovery of Kyrgyz-born gangster Almanbet Anapiyaev's corpse was "without doubt" the consequence of a "criminal showdown" in the Belarussian capital, allegedly involving the brother Kyrgyzstan's former authoritarian president Kurmanbek Bakiyev.

French President Francois Hollande said Tuesday he was going to Minsk with the "strong will" to achieve a peace deal on Ukraine at a four-way summit also attended by German Chancellor Angela Merkel.

The Russian and Ukrainian leaders were also due to be present at the meeting in the Belarusian capital Wednesday, as fighting rages on in the east of Ukraine.

The foreign ministers of Russia, Ukraine, Germany and France ended their latest Berlin crisis meeting Wednesday with a joint call to cease hostilities in Ukraine but no breakthrough agreement to stop the bloodshed.

The talks had been held against the unpromising backdrop of fresh clashes between Ukrainian government forces and pro-Moscow rebels in the east of the former Soviet republic, and after Ukraine's president accused Moscow of fueling the war with fresh troops and tanks.

Ukrainian and pro-Russian rebel leaders tried on Friday to revive peace talks that stalled after just one round due to stark difference over how to end the eight-month separatist war.

A tense meeting mediated by European and Russian envoys in the Belarussian capital Minsk on Wednesday was due to have been followed by a final one on Friday at which a comprehensive peace accord was signed.

Ukrainian and rebel envoys resumed intense talks on Wednesday aimed at ending a pro-Russian uprising that has left the ex-Soviet republic in ruins and upset East-West ties.

A successful round of preliminary negotiations in the Belarussian capital Minsk would pave the way for a second meeting on Friday at which a final agreement is signed.

Kazakh President Nursultan Nazarbayev followed his Belarusian counterpart to Ukraine on Monday as Moscow's old allies reassessed their reliance on Russia in the heat of its financial malaise.

The authoritarian leader of Belarus visits Kiev on Sunday hoping to revive stalled Ukrainian peace talks he has been hosting in order to calm Europe's volatile eastern edge.

But a high-ranking Ukrainian official said Belarussian President Alexander Lukashenko will be just as keen to use the trip to build bridges to Europe that ease his dependence on an increasingly isolated Russia.

Belarus has detained a leading defense journalist and charged him with treason and espionage, his daughter told Agence France-Presse on Monday after she was summoned to the KGB security services.

Alexander Alesin has been accused of "giving out state secrets to a foreign country, organization or its representative, or espionage," his daughter Olga told AFP.

Rights activists on Friday urged Belarus's KGB security services to reveal the location of a well-known defense journalist who went missing more than a week ago and is suspected to have been detained.

Alexander Alesin, a journalist at the independent newspaper Belarussians and the Market who specializes in defense and the arms trade, has not come to work since November 26 and his cell phone is switched off, his colleagues said.

A Belarusian journalist who specializes in defense has been missing for several days, his colleagues said on Thursday, raising fears he has been detained by security forces.

Journalist Alexander Alesin "has not come to work for several days now," Irina Krylovich, deputy editor of Belarusians and the Market independent newspaper where the journalist works in Minsk, told Agence France-Presse.