The operator of the crippled Fukushima Daiichi nuclear power plant says it has retrieved samples from inside the No. 1 reactor containment vessel. It says the samples are likely to contain fuel debris.

The plant suffered a triple meltdown in the March 2011 earthquake and tsunami.

Its operator, Tokyo Electric Power Company, or TEPCO, said on Wednesday that underwater robots successfully sucked water out from two locations inside the vessel.

The company has been examining the inside of the No.1 reactor containment vessel. It says the accumulated matter at the bottom is thought to contain fuel debris.

The project to collect samples initially began early last month, but was suspended due to technical errors. It was resumed on Tuesday.

Experts hope that a close analysis of the samples will help lead to successful removal of fuel debris -- one of the greatest challenges in the plant's decommissioning process.

TEPCO said it will try taking samples from two other locations inside the vessel. It also said it will spend about a year identifying the types and amounts of chemical elements contained in the samples.

The company also plans to send robotic cameras inside the pedestal, a structure that props up the reactor.