FORT HOOD: US President Barack Obama led his nation in mourning today as shocked Americans struggled to understand why a Muslim army doctor killed 13 in a massacre at a US military base.

Alleged shooter Major Nidal Malik Hasan, 39, a psychiatrist and specialist in combat stress who had been about to deploy to Afghanistan against his wishes, also wounded 30 people in Thursday’s rampage.

Speculation swirled at Fort Hood, Texas, as to whether the alleged shooter had snapped under the pressure of his job counselling thousands of war-weary troops, or was motivated by deeper convictions.

In his weekly radio address today, Obama sought to reassure US soldiers.

“Thursday’s shooting was one of the most devastating ever committed on an American military base,” he said. “And yet, even as we saw the worst of human nature on full display, we also saw the best of America.” The president noted that soldiers and civilians rushed to help, tearing off bullet-riddled clothes to treat the injured and using blouses as tourniquets.

Obama ordered flags to fly at half-staff at the White House and federal buildings, as troops here and around the world held a minute’s silence to mourn the dead.

Obama would also attend a memorial service due to be held in the coming days, the White House said.

The bodies of those killed were taken to the same mortuary at Dover Air Base in Delaware that handles fallen soldiers from the wars in Afghanistan and Iraq, the Pentagon said on Friday.

Hasan was moved, meanwhile, from a civilian to a military

hospital, in part for security reasons, Fort Hood deputy commander Colonel John Rossi told reporters.

Witnesses reportedly heard Hasan shout “Allahu Akbar!” as he opened fire in a troop processing centre with a semiautomatic weapon and a handgun.

Rossi said investigators believe Hasan fired more than 100 rounds during the incident.

A surveillance video aired by CNN showed the major buying breakfast wearing traditional Muslim garb at a base store just hours before the shooting.

The New York Times reported that on Wednesday and Thursday, Hasan seemed in a hurry to give his belongings, including a copy of the Koran, to a neighbour. “I’m not going to need them,” he told the neighbour, Patricia Villa, according to NYT.

Obama delays Japan visit

TOKYO: US President Barack Obama has delayed his visit to Japan next week by one day following a deadly shooting at a military base in Texas, Prime Minister Yukio Hatoyama said on Saturday. Japanese national broadcaster NHK and Jiji Press reported that Washington had asked Tokyo to change the schedule for the two-day visit to allow Obama to attend a memorial service for the 13 people killed in Thursday’s shooting. Obama had been due to arrive for his first trip to Japan on Thursday for talks with Hatoyama and to meet Emperor Akihito.

Obama would now be arriving on Friday and stay until Saturday. — AFP