Gunmen in Mali have killed at least five people in an attack on a hotel in the central town of Sevare, officials say. The dead include Malian soldiers.
The UN mission in the country said it believed "a member of the international personnel" was killed in the attack.
An unknown number of hostages are still being held at the Byblos Hotel, which is popular with UN workers. Two of the gunmen have also been killed.
Mali has been fighting Islamist rebels in the north for a number of years.
A spokesman for the Russian embassy in Mali said one of those being held was a Russian citizen. Earlier, officials in Kiev said a Ukrainian citizen was also believed to have been captured.
Army spokesman Lt Col Diarran Kone told Associated Press that the operation to free hostages was ongoing.
One source told Agence France-Presse early on Saturday that a number of hostages had been freed and evacuated but this has not been independently confirmed.
In a statement, the UN mission in Mali (Minusma) condemned the "despicable attack in the strongest terms".
The mission said "shots continue to be fired sporadically at the hotel and in its vicinity".
The BBC's Alex Duval Smith in Mali says the town, which is about 600km (370 miles) north-east of the capital, Bamako, is a trading hub that serves the historic riverside city of Mopti.
A local resident told the BBC that it was the first time the city has been hit by an attack like this.
"Since the beginning of the fighting in Mali, we haven't experienced such a situation in Sevare.
"We would expect these things to happen in Gao or Timbuktu, but this the first time it has happened in Sevare," he said.
Al-Qaeda-linked militants have been fighting the army in northern Mali.
France, the former colonial power in Mali, intervened in January 2013 to stop their advance south to the capital.
Militancy in Mali
- October 2011: Ethnic Tuaregs launch rebellion after returning with arms from Libya
- March 2012: Army coup over government's handling of rebellion
- April 2012: Tuareg and al-Qaeda-linked fighters seize control of north
- June 2012: Islamist groups capture Timbuktu, Kidal and Gao from Tuaregs, start to destroy Muslim shrines and manuscripts and impose Sharia
- January 2013: Islamist fighters capture a central town, raising fears they could reach Bamako. Mali requests French help
- July 2013: UN force, now totalling about 9,750, takes over responsibility for securing the north after Islamists routed from towns
- July 2014: France launches an operation in the Sahel to stem emergence of jihadist groups
- Sporadic attacks continue in desert area of northern Mali, blamed on Tuareg and Islamist groups