The largest forest fire since 1991 in the zone of exclusion around the Chornobyl nuclear power plant, scene of the world's worst nuclear power accident, has been successfully contained, Ukrainian Prime Minister Arseny Yatsenyuk said on April 29.

A total of 320 hectares of forest caught fire on April 28 only 30km from the decomissioned power plant, and spread to within 5km of disposal sites of radioactive waste before it could be contained, emergency services reported

"I have been informed that the fire was contained as of 12:45," Yatsenyuk said, addressing a government meeting, as quoted on the government website. Yatsenyuk said that radiation level were under 21 micro Roentgens per hour in the exclusion zone and 11 in Kyiv.

Nuclear safety specialist Serhiy Zibtsev said that radiation released by the fire could reach a dangerous level for the firefighters. "This is mainly a grass fire, with a low temperature and thus less disturbance of polluted soil. If the actual forest catches fire, the level of pollution will be higher. But now the fire has been localised," he told TV channel 1+1.

Ukraine's interior ministry said that a criminal investigation had been opened into the causes of the fire. Acting head of the State Emergencies Service Zorian Skyriak reported that fires had broken out at 15 different locations, which might point to arson.

International donors attending a support conference for Ukraine on April 27 promised up to €150mn in extra funding to secure the site of the Chornobol power plant against leakage of radiation. April 26 marked the 29th anniversary of the disaster.