The sister and father of an American photojournalist taken hostage by Al Qaeda in Yemen have added their public pleas for his captors to spare his life.

Luke Somers was kidnapped in September 2013 in the Yemeni capital of Sanaa, where he had been working as a freelance photographer for the Yemen Times.

Al Qaeda posted a video Thursday that showed Somers, 33, and a local Al Qaeda commander threatening that Somers would meet his fate in three days if the United States doesn't meet the group's demands, which weren't specified.

In a video posted Saturday near London, Lucy Somers describes her older brother as a romantic who "always believes the best in people." She ends with the plea: "Please let him live."

In a statement, Somers' father, Michael, calls his son "a good friend of Yemen and the Yemeni people" and asks for his safe release.

"When foreign nationals were advised to leave Yemen, Luke refused to go, saying he felt safe and at home there," Lucy Somers said in her video. "He felt the Yemeni people would look after him."

"Photojournalism has been his way of highlighting the struggles of the Yemeni people," she said.

Michael Somers said his son "was confident that no one would harm him for his simplicity and honest friendship to all Yemenis around him."

Luke Somers "told all his friends and loved ones stories of Yemenis' generosity, humility and devoted friendship," his father said, adding, "Luke's life in Yemen these past three and a half years should not have ended with a kidnapping but with a great reward. The fact that he chose to live in Yemen and not the United States shows where his sympathies lay. Please bring Luke back to us safe and sound."

Somers' brother, Jordan, and mother, Paula, offered a similar message in an earlier video.

"My life is in danger," Luke Somers said in the Al Qaeda footage, which appeared to mimic hostage videos released by Al Qaeda's rival, the Islamic State group. He asked for help.

In a statement Thursday, Pentagon press secretary Rear Adm. John Kirby acknowledged for the first time that a raid last month had sought to rescue Somers but that he turned out not to be at the site.

White House spokeswoman Bernadette Meehan also said President Barack Obama had authorized a rescue operation to free Somers and other hostages but "regrettably, Luke was not present."