Somers was alive but badly injured when Special Forces from the U.S. reached him during the rescue mission, a national security officer from Yemen said. The officer also said the al-Qaeda militants holding Somers had shot him.
Sources said Somers died shortly thereafter when he was transported to another location for medical treatment.
In the rescue attempt, Yemen and U.S. forces and a drone strike before the rescue attempt killed 10 militants, said Yemeni officials.
Chuck Hagel the U.S. Secretary of Defense said through a prepared statement that Somers and a hostage who was not from the U.S. had been murdered by the al-Qaeda militants during the operation.
Pierre Korkie a hostage from South Africa was reportedly the other hostage who was killed during the operation.
U.S. President Barack Obama released a prepared statement on Saturday morning condemning the murder of Luke Somers by the terrorists.
Obama said he had ordered the mission on Friday.
A top security official in Yemen said that Somers was scheduled to die on Saturday. The al-Qaeda militants were preparing to execute him.
President Obama, John Kerry the Secretary of State and Hagel all expressed condolences to the family of Somers.
A sister of Somers learned of the death of her brother from agents in the FBI. Lucy Somers said her family was asking for peace.
The local branch of the al-Qaeda in Yemen, known as the Al-Qaeda in the Arab Peninsula uploaded a video on Thursday showing Somers and threatening to execute him in three days if the U.S. would not meet the demands of the group,
The failed mission comes after a drone strike by the U.S. in Yemen that killed many alleged militants in al-Qaeda. The strike hit at dawn in the southern province of Shabwa, striking a militant hideout said the official.
In that airstrike, there were six militants killed and possibly more.
Lucy Somers said her father had pleaded with the group through a video to let his son go alive.