A uniformed man blew himself up in the midst of a military parade rehearsal attended by senior officials in the Yemeni capital Sanaa on Monday, killing at least 41 people and wounding more than 60, a police source said.
Yemen's defense minister chief of staff were present at the event but were not hurt in the blast, a military source said.
The attack coincided with a US-backed Yemeni army offensive against al-Qaida-linked militants in the south of the country, where they control several towns. Troops closed in on one of their strongholds on Sunday in heavy fighting.
Militants have exploited political instability in Yemen to gain a foothold in a country paralyzed for most of 2011 by protests that eventually unseated President Ali Abdullah Saleh.
Yemen is home to al-Qaida in the Arabian Peninsula (AQAP) and is viewed by the United States as a major threat, not only to regional security but its own. A US military instructor was wounded in an ambush on a US training team on Sunday.
Blood and body parts were scattered across the 10-lane road where the rehearsal was being held on Monday morning. The area was cordoned off with yellow tape and a forensic team was examining the site.
"We were in a parade, suddenly there was a huge explosion. Dozens of our men were killed. We tried to help them," said a man who identified himself as Colonel Amin al-Alghabati, his hands and uniform flecked with blood.
"The suicide bomber was dressed in a military uniform. He had a belt of explosives underneath," he said.
A Reuters witness said the wounded were being ferried to hospital in taxis. The impoverished state has seen a spate of deadly attacks since President Abd-Rabbu Mansour Hadi replaced Saleh in February saying he would extinguish an Islamist insurgency, which until now has been concentrated in the south.
The Yemeni army earlier this month launched an offensive in the southern province of Abyan to regain control of territory and towns seized by militants calling themselves Ansar al-Sharia (Partisans of Islamic Law).
The parade was scheduled for Tuesday to mark Yemen's national day, which commemorates the unification of north and south Yemen, previously separate states, and Hadi was due to attend.
"Yemenis must stand together in the face of this deadly terrorist threat," said Brigadier Karim Nahil. "We will celebrate our unity tomorrow with the blood of our martyrs on our hands and faces."

JPost.com