The severity rating of the nuclear crisis at Japan’s Fukushima plant has been raised to the most severe rating on the international nuclear scale.

The level was increased from five to a seven, putting it on par with the Chernobyl disaster in 1986.

Japanese officials believe the amount of radiation released is only a tenth of what was released in the Chernobyl disaster, while acknowledging they eventually could exceed Chernobyl’s emissions if the crisis continues.

“This reconfirms that this is an extremely major disaster. We are very sorry to the public, people living near the nuclear complex and the international community for causing such a serious accident,’ said Chief Cabinet Secretary Yuki Edano.

But Edano told reporters that there was so far no “direct health damage” from the crisis. “The accident itself is really serious, but we have set our priority so as not to cause health damage.”

But, the International Atomic Energy Agency, the UN nuclear watchdog, said this designation indicates a major release of radioactive material with widespread health and environmental effects, requiring implementation of planned and extended countermeasures.

Greenpeace suggests the Fukushima situation is worse than Chernobyl because this is a more populated area.

The plant was damaged in a massive tsunami March 11 that knocked out cooling systems and backup diesel generators, leading to explosions at three reactors and a fire at a fourth that was undergoing regular maintenance and was empty of fuel.

The magnitude-9.0 earthquake that caused the tsunami immediately stopped the three reactors, but overheated cores and a lack of cooling functions led to further damage.

Engineers have pumped water into the damaged reactors to cool them down, but leaks have resulted in the pooling of tons of contaminated, radioactive water that has prevented workers from conducting further repairs.

A month after the disaster, more than 145,000 people are still living in shelters. The quake and tsunami are believed to have killed more than 25,000 people, but many of those bodies were swept out to sea and more than half of those feared dead are still listed as missing.