Osaka: Japan's Prime Minister Naoto Kan on Tuesday said that his government is on high alert over the crisis at the stricken Fukushima nuclear plant, a daily reported.

Kan told a lower house budget committee meeting that the situation continues to be unpredictable and that the government will tackle the problem while in a state of maximum alert, a daily reported.

Radiation worries have disrupted efforts to restart the cooling system of the Fukushima Daiichi plant, which was battered by a huge earthquake and tsunami on March 11 that left more than 28,000 people dead or missing.

Plutonium has been detected in soil at the facility northeast of Tokyo and highly contaminated water has leaked from a reactor building, the operator said yesterday, while nearby seawater has shown high iodine readings.