Forensic policemen collect evidence at the site of the bomb blast in Sanaa on Monday. (AFP)

Washington, May 21: Yemen was rocked by its worst terrorist bombing in years today when a suicide attacker disguised as a Yemeni soldier blew himself up in the midst of a military parade rehearsal near the presidential palace in Sanaa, the capital. Yemeni officials and hospitals said at least 90 people were killed.

Suspicion fell instantly on al Qaida’s affiliate in Yemen, which has been fighting a bloody battle in recent days against the Yemeni military for control of towns in Yemen’s lawless south. The US, increasingly concerned about the militants’ widening influence in Yemen, has assisted the fight with a stepped-up campaign of drone strikes and military assistance.

The suicide bombing brought scenes of horrific carnage to a central square in Yemen’s capital, which had been spared the worst of the insurgent violence. “I saw arms and legs scattered on the ground,” said one young soldier named Jamal. “The wounded people were piled on top of each other, covered with blood. It was awful.”

A video of the parade ground posted on YouTube showed throngs of rehearsal participants running in panic and a pile of motionless uniformed bodies following the explosion. The bombing came amid an intensive battle by the Yemeni military to retake a southern town that has been controlled by militants allied with al Qaida’s affiliate in Yemen.

The parade rehearsal bombing came as the defence department in Washington confirmed that three American civilian contractors helping to train Yemen’s coast guard were attacked yesterday by militant gunmen in Yemen’s port city of Hodeida.

The suicide bombing attack in Sanaa appeared to catch the Yemen defence forces totally by surprise and presented a major new challenge to President Abdu Rabbu Mansour Hadi. He took power in February from former President Ali Abdullah Saleh, the autocratic ruler whose unwillingness to cede power had long been an underlying cause of the mayhem in the country.