At least 90 people are now known to have died in this morning's suicide bomb attack in the Yemeni capital, Sanaa.
A police source said a man in a soldier's uniform blew himself up at a military parade rehearsal.
Hundreds of injured are being treated in seven hospitals across Sanaa. All the dead and injured are soldiers.
There has been no claim of responsibility for the massive blast.
Yemeni police officer Colonel Abdul Hamid Bajjash, in charge of security at the blast area, said the attack "bears the hallmark of Al-Qaeda."
The unidentified bomber detonated his explosives as soldiers from the government's central security forces, commanded by a nephew of former president Ali Abdullah Saleh, rehearsed for an army parade to mark the 22nd anniversary of the unification of north and south Yemen.
Yemen's defence minister, Mohammed Nasser Ahmed, was present at the time of the explosion but escaped unharmed, the official added.
Today's attack is Sanaa's most deadly since President Abdrabuh Mansur Hadi took power in February with a pledge to fight al-Qaeda's growing presence in the county.
Mr Hadi, who was elected in a single-candidate vote as stipulated by the Gulf-sponsored transition deal that forced Saleh from office, was expected to give a speech at the military ceremony tomorrow.
It remains unclear if the parade will take place as planned.
The suicide bombing comes 10 days into a massive army offensive against al-Qaeda in Yemen's restive southern Abyan province, where the jihadists have seized control of a string of towns and cities in attacks launched since May last year.
In a separate incident today, al-Qaeda militants attacked a Yemeni military base in Wadi Hassan, east of Zinjibar, killing seven soldiers and wounding 23 others, military officials and medics said, adding that fierce fighting also erupted northeast of the city.
Since the offensive began, 234 people have been killed, according to a tally compiled by AFP, including 158 al-Qaeda fighters, 41 military personnel, 18 local militiamen and 17 civilians.
