The captain and crew of a South Korean ferry that capsized last week with hundreds of children on board acted in a way "tantamount to murder," President Park Guen-Hye said Monday, as four more crew members were arrested.

Park's denunciation, in which she vowed to hold all those responsible for the disaster "criminally accountable", followed the release of a transcript showing the panic and indecision that paralysed decision-making on the bridge as the 6,825-tonne Sewol listed and capsized Wednesday morning.

The confirmed death toll stood at 64 but was expected to rise dramatically with 238 people still unaccounted for.

"The actions of the captain and some crew members were utterly incomprehensible, unacceptable and tantamount to murder," Park said in a meeting with senior aides.

"Not only my heart, but the hearts of all South Koreans have been broken and filled with shock and anger," said Park, who was heckled Thursday when she met relatives of the hundreds of passengers still missing -- most of them schoolchildren.

The families have criticised the official response to the disaster, saying the initial rescue effort was inadequate and mismanaged.

The president said it was increasingly clear that Captain Lee Joon-Seok had unnecessarily delayed the evacuation of passengers as the ferry started sinking, and then "deserted them" by escaping with most of his crew members.

Ethically 'unimaginable'

"This is utterly unimaginable, legally and ethically," she said.

Lee was arrested on Saturday along with a helmsman and the ship's relatively inexperienced third officer, who was in charge of the bridge when the ship first ran into trouble.

Three more officers and an engineer were detained by police on Monday and could, prosecutors said, face similar charges of criminal negligence and deserting passengers.

A transcript released of the final radio communications between the Sewol and marine traffic control suggested a scene of total confusion as the vessel listed sharply to one side.

In the end, the evacuation order was only given around 40 minutes after the ship ran into trouble, by which time it was listing so heavily that escape was almost impossible.

"Precious minutes just wasted," was the front page verdict of the Dong-A Ilbo daily on Monday.

Lee has insisted he had acted in the passengers' best interest, delaying the order to abandon ship because he feared people would be swept away and drowned.

Meanwhile, local TV stations aired excerpts Monday of a 2010 promotional video in which Lee said ferries offered the safest public transport "as long as you follow the instruction of our crew".

Realistic hopes of finding survivors have disappeared, but families of the missing are still opposed to the use of heavy cranes to lift the ship before divers have searched every section.

It took divers more than two days to access the submerged ferry and the first bodies from inside the vessel were only recovered on Sunday.

Divers to focus on cabins

Coastguard officials said 24 had since been pulled out, but hundreds more are likely trapped inside.

"We believe there are many people on the third and fourth decks where cabins were located, so we will focus on these areas," a coastguard spokesman told reporters.

"We have also opened a route leading to a dining hall, and will try to enter that area," he said.

Of the 476 people on board the Sewol, 352 were high school students headed for the holiday island of Jeju.

South Koreans have been stunned by the tragedy, which looks set to become one of the country's worst peacetime disasters and has unleashed a sense of profound national grief.

The weeping of devastated family members could be heard across the harbour on Jindo island as boats brought the most recently recovered bodies in from the nearby rescue site Monday morning.

Wrapped in white cloth, each body was gently lifted off the boats and placed on a stretcher which was then carried away by six uniformed police wearing surgical face masks.

In a nearby tent they were placed on white tables and prepared as best as possible for the grieving relatives to make a visual identification.

The families have bitterly criticised the official response to the disaster, saying delays in accessing the submerged ship may have robbed any survivors of their last chance to make it out alive.

In her comments Monday, Park said the government should review its crisis response system.

A director-level official at the public administration ministry was dismissed from his post Sunday after taking a souvenir photo on Jindo island in front of a list of the dead.