Foreign Office Minister Alistair Burt condemned the "cowardly" suicide bomb attack which killed 96 soldiers in Yemen today.
"The UK condemns today's violent attack in central Sana'a in which scores of Yemeni servicemen were killed and many more injured," Mr Burt said.
"This tragic event underlines the scale of the security challenge facing the Yemeni government as it seeks to introduce key reforms and work towards completing political transition."
"This cowardly attack must not be allowed to stall or prevent progress towards the completion of rigorous reform. As we prepare to meet in Riyadh ... we are resolute in our support for President Abd Rabbuh Mansour Hadi as he leads his nation towards a safer and more prosperous future," he said.
Mr Burt is due in Saudi Arabia on Wednesday for a meeting of the Friends of Yemen group, which Britain co-chairs.
Al Qaeda's wing in Yemen said a suicide bombing that killed 90 people was in revenge for what it called the U.S. war on its followers in southern Yemen and that it had targetted the Yemeni defence minister and his top commanders.
The group also warned in a statement received by Reuters that more attacks will follow if the military campaign in the southern province of Abyan did not stop.
"We will take revenge, God willing, and the flames of war will reach you everywhere, and what happened is but the start of a jihad project in defence of honour and sanctities," the statement, addressing Yemeni military commanders, said.
President Abd-Rabbu Mansour Hadi has vowed that Yemeni security forces will step up their efforts to clamp down on militants after a suicide bombing at a military parade rehearsal in Sanaa killed 90 people.
"Our armed forces and security forces will become tougher and more determined in pursuing terrorists," the state news agency Saba quoted Hadi as telling victims' families in a condolence message.
Video as the investigation in to the blast in Yemen gets under way:
96 people have been killed after 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, security sources say.
300 more people were wounded.
Reuters report that at least 10 people were killed and 20 wounded in an attack by a suicide bomber on soldiers practising for a military parade in the Yemeni capital Sanaa on Monday.