A diver taking part in search operations inside the sunken ferry Sewol died Friday after suffering from breathing difficulties, officials said.

The diver, who took part in operations to cut open windows at the back end of the submerged hull, complained of breathing difficulties and was flown to a nearby hospital by helicopter, but was pronounced dead soon after, the officials said.

The government's disaster response team is scheduled to hold a press conference later in the day to explain the details of his death as well as plans for the search operations going forward.

Work began Thursday to cut open three windows at the back of the fourth deck. Divers plan to use the windows to remove obstacles blocking access to parts of the hull, where some of the missing are believed to be trapped.

"So far, a length of 4.8 meters has been cut along the bottom of the windows," an official of the government's disaster response team said in a press briefing earlier in the day. "We expect the work to be complete as soon as within one or two days."

The glass in the windows have already been broken, but two more areas above the windows and the lower parts of the windows'
vertical sides have yet to be cut open, the official said.

Divers also plan to continue the search for bodies across the third, fourth and fifth decks.

The operations will take place simultaneously at set times during the day when currents virtually come to a standstill, the officials said. On Friday, those times were 8:57 a.m., 2:38 p.m. and 8:28 p.m.

Officials also said they plan to consult experts later in the day after family members of those missing requested to have the front part of the hull also cut open.

The structure of the front part, however, is more complicated than the back, which is likely to make it difficult to pull out large obstacles even if holes are made, they said.

No bodies have been recovered from the sunken ferry since May 21, leaving the death toll at 288. Sixteen people remain accounted for.

The 6,825-ton Sewol was carrying an estimated 476 people on board when it sank off the southwestern island of Jindo on April 16. (Yonhap)