The US Coast Guard said Monday it has discovered a body from the lost El Faro cargo ship, which is believed to have sunk in the Atlantic with 33 people aboard.

Several survival suits were found and searchers "did identify human remains in one," Coast Guard Captain Mark Fedor said. "We are assuming that the vessel has sunk," he told reporters.

"We are still looking for survivors or any signs of life, any signs of that vessel."

Following days of stormy weather from Hurricane Joaquin, searchers Sunday were finally able to see "a lot of material that was at sea," he said.

While en route from Florida to Puerto Rico with 28 Americans and five Poles aboard, the 735-foot El Faro lost contact early Thursday as the dangerous weather system approached the Bahamas.

It was reported to be caught in the storm near the chain's Crooked Island, where the ship sent a satellite notification stating it had lost propulsion and had a 15-degree list.

If the crew abandoned ship Thursday, it would have been into a Category Four hurricane packing 140-mile-per-hour winds, 50-foot (15-meter) seas and near zero visibility, Fedor said.

"Those are challenging conditions to survive in," he noted, adding that people can usually stay alive about four to five days in warm water.

Fedor said that the Coast Guard had "covered 70,000 square nautical miles" on Sunday and that it was believed that the ship "sank in the last known position that we recorded on Thursday."

- Focus: 'people in water' -

"We've modified our search efforts to focus more on potential people in the water, life boats and life rafts," Fedor said.

Items recovered from the ship so far include a life ring and life boat.

Searchers also checked life rafts, life boats and survival suits, looking for signs of life.

"We were hoping to find a survivor so we needed to check every one. We did identify human remains in one of the survival suits," Fedor told reporters, adding that there were "no other signs of life at this time."

The body, he said, was unidentifiable and the Coast Guard had not been able to recover it.

"We continue to hold out hope for survivors. Our prayers and thoughts go out to the family members and we will continue to do all we can to support them," Tim Nolan, president of the company that owns El Faro, said in a statement Monday.

The Coast Guard is searching two debris fields -- one about 300 square nautical miles near El Faro's last known position.

The other, around 60 miles (97 kilometers) to the north, spans some 70 square miles.

El Faro was carrying 391 containers in addition to 294 trailers and automobiles below deck when it disappeared, making the ship vulnerable in a storm.

In addition, Fedor said, "the worst spot for any ship to be in is when you're disabled, you've lost all propulsion, you have you no means to move that vessel.

"You become very susceptible. You fall into the trough, basically, between the waves," he said.

Three Coast Guard cutters are on scene in addition to "three commercial tugs that were hired by the shipping company. And we have a full schedule of aircraft that are flying all day today," Fedor said.

The boats are expected to continue to search into the night.

"We will hopefully find survivors," Fedor added. "That is our focus as we move forward."

The National Transportation Safety Board will lead an investigation into the accident, aided by the Coast Guard, which will likely conduct a separate investigation.

Hurricane Joaquin was still swirling in the Atlantic Monday far from the Bahamas, as a much weakened Category One storm on the five-point Saffir-Simpson scale, according to the US National Hurricane Center.

Located about 185 miles (300 kilometers) north of Bermuda, the storm was traveling northeast packing 85 mile-per-hour (140 kilometer-per-hour) maximum sustained winds.