Washington - Senior US senator Joe Lieberman has called for a congressional investigation to establish whether the mass shooting at the US Army's Fort Hood in Texas were motivated by terrorism. There had been "strong warning signs" that the alleged gunman, Army psychiatrist Major Nidal Malik Hasan, who killed 13 people and injured another 38, was an "Islamist extremist,"Lieberman said on Fox News television.
"If that is true, the murder of these 13 people was a terrorist act and, in fact, it was the most destructive terrorist act to be committed on American soil since 9/11," he was quoted as saying.
Hasan, a devout Muslim, could have turned radical and the probe should determine whether the army missed any clues that he held extreme views, said Lieberman.
The senator, who ran as Democrat candidate for the vice-presidency in 2000, chairs the Senate Homeland Security Committee.
