A video distributed Saturday on the Internet showed what appears to be a Japanese hostage saying that a fellow Japanese captive had been executed and outlining a new militant demand for his release.
In the video, the hostage, a man identified as Kenji Goto, a Japanese journalist, appears to be holding a photo of his countryman, Haruna Yukawa, who has been beheaded, according to the SITE Intelligence Group, which monitors extremist websites. SITE said the video was released on militant Twitter accounts.
Yukawa's father, Shoichi Yukawa, 74, told reporters at his home in Chiba, Japan, on Sunday that he had received a phone call from the Foreign Ministry around midnight Saturday telling him that his son apparently had been slain, although there was no official confirmation.
"My mind totally went blank. I cannot find any other words," Yukawa told reporters at his home, according to Japan's Kyodo news agency. "My heart aches that it has turned out to be like this. I hope it is not my son, but I just feel awful."
Yukawa told journalists his son had regarded the remaining hostage, journalist Kenji Goto, like a big brother. "Mr. Goto risked his life to go [to Syria] because he was worried about my son. I feel very bad about this," Yukawa said, according to Kyodo.
Both men were believed to have been abducted in Syria last year by the Islamic State. The militant group demanded that Japan hand over $200 million for their release. But Friday's deadline for the ransom payment passed without any word of their fate.
The case has drawn a great deal of attention in Japan and spawned a crisis for the government of Prime Minister Shinzo Abe, who had vowed to do what he could to save the two men. Japanese authorities said they were studying the video.
President Obama, in a statement issued by the White House, said, "The United States strongly condemns the brutal murder of Japanese citizen Haruna Yukawa by the terrorist group" Islamic State.
"We stand shoulder to shoulder with our ally Japan and applaud its commitment to peace and development in a region far from its shores."
Abe said that an "image in which Mr. Haruna Yukawa seems to have been murdered was uploaded online."
"Fully aware of unbearable pain and sorrow that his family must be feeling, I am simply left speechless."
In the video, the captive journalist says that Islamic State has dropped its ransom demand and is now proposing a new deal: his release in exchange for the freedom of Sajida Rishawi, a female suicide bomber captured when she attempted to attack a hotel in Jordan in 2005 as part of series of militant attacks.
"It's simple: You give them Sajida and I will be released," Goto says, according to a transcript provided by SITE. "At the moment, it actually looks possible," adding that Japanese government officials working for his release were in Jordan, where the woman is being held.
In the video, Goto says Abe responsible was for Yukawa's death. "You did not take the threats of my captors seriously and you did not act within the 72 hours," he says.
He also had a message for his "beloved wife," Rinko.
"I love you, and I miss my two daughters," he tells his wife. "Please don't let Abe do the same for my case," referring to the apparent fate of Yukawa.
"Don't give up. You along with our family, friends, and my colleagues in the independent press must continue to pressure our government. Their demand is easier. They no longer want money. So you don't need to worry about funding terrorists."
Rishawi was a failed participant in the 2005 suicide assaults on three hotels in Amman that left 57 dead and 90 wounded, Jordanian authorities say. Her explosive belt did not detonate and she was captured, Jordanian police say.
Her husband, who was one of the three successful attackers — all of them Iraqi, as is Rishawi — set off his suicide bomb during a wedding party at the Radisson Hotel, authorities said.
Islamic State previously beheaded five Western hostages: two U.S. journalists, an American aid worker and two British aid workers.