The Fukushima Daiichi nuclear power plant experienced full meltdowns at three of the plant’s reactors, a nuclear agency was quoted as saying to CNN.

An evaluation from Japan’s Nuclear Emergency Response Headquarters goes further than previous statements describing the extent of the damage following the earthquake and tsunami in March.

The agency reportedly said units 1, 2 and 3 experienced full meltdowns.

Tokyo Electric Power Co. (TEPCO), the plant’s owner, said fuel rods in units 2 and 3 may have melted during the first week of the disaster and that a major part of fuel rods in Unit 2 melted and fallen to the bottom of the pressure vessel. Unit 1’s fuel rods melted within the first 16 hours of the disaster and are now sitting at the bottom of thepressure vessel, which is now believed to be leaking.

Parts of the fuel rods in Unit 3 are also believed to be sitting at the bottom of the pressure vessel, the article said.

Staff members of the U.S. Nuclear Regulatory Commission (NRC) were quoted as saying to Bloomberg that they believed the cores were melting early on in the crisis. A Japanese nuclear engineer told a panel of U.S. scientists on May 27 that nuclear fuel at the plant began melting just hours after the earthquake struck.

TEPCO, however, reportedly estimates a full meltdown did not occur in units 2 and 3.

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