Pope Francis said on Monday he was unable to maintain neutrality before the victims of a South Korean ferry tragedy because their suffering was "human."

"Someone came up to me to suggest that I take off the yellow ribbon (I received from the bereaved families) to maintain neutrality," he told reporters aboard his flight back to the Vatican, when asked about the risk of his concern for the victims being used to further political agendas in South Korea. "But I told the person that I couldn't in front of human suffering."

The pontiff had just wrapped up his visit to South Korea, during which he sought multiple chances to speak to the victims and baptized one of them with his own papal name, Francis.

He was still wearing the yellow ribbon, which has become the symbol of the April tragedy, on his chest during the news conference.

The ferry Sewol capsized off South Korea's southwest coast on April 16, killing more than 300 people, mostly high school students.

Survivors and families of the deceased have been demanding an independent probe into the disaster and that the government give a related committee special authority to indict those responsible.

"I believe the fathers, mothers and siblings of the (Sewol) victims are going through immeasurable pain," the pope said. "My words of comfort cannot give new life to the dead but can allow us to unite through consolation.

On a separate note, the pontiff said he was impressed by Korean women who had been forced into sexual slavery during World War II.

"When I met them (on Monday), I realized they hadn't lost their human integrity," he said. Francis had invited seven of the "comfort women" to his final Mass in Seoul.

"They were exploited and enslaved, but I wonder what would have allowed them keep their integrity Historians say an estimated 200,000 young women, mostly from Korea and China, were coerced into sexual servitude by the Japanese imperial army during the war. (Yonhap)