A bomb blast hit an anti-U.S. protest in northern Yemen on Friday, injuring at least 22 people, a rebel group that controls much of the north of the country said.
In a statement, the leader of the Houthi movement - Shi'ite rebels that Yemen's military tried to crush in campaigns in 2004-2009 - said the bombing took place in the province of Saada, on Yemen's northwestern border with Saudi Arabia.
It did not say who it believed carried out the attack.
The conflict with the Houthis is one of several facing Yemen's new president, Abd-Rabbu Mansour Hadi, as he tries to implement a power transfer backed by Riyadh and Washington.
The transition plan is aimed at averting civil war among an army divided between foes and allies of former President Ali Abdullah Saleh.
Mass protests against him last year were coupled with fighting between pro- and anti-Saleh units. Saleh eventually became the fourth veteran Arab leader unseated by "Arab Spring" protests.
The transition plan calls for Hadi and an interim government made up of Saleh's party and opposition blocs to lead Yemen to elections and write a new constitution within two years.
The plan did not include the Houthis, who have held talks with the U.N. envoy attempting to implement the deal aimed at bringing them into a political process.
'Having a united island at peace with itself and its neighbours will create more jobs, more prosperity. So, the solution will pay for itself,' UN envoy says
EU president believes Russian airstrikes in Syria 'are making an already very bad situation even worse'
Zeid Ra'ad Al Hussein says the Working Group, although not a court, based its decision on binding international law and that Britain and Sweden should therefore abide by its findings
TIKA releases details of dozens of projects in education, infrastructure and agriculture
'I think we will take very seriously the request from Turkey and other allies to look into what NATO can do to help them cope and deal with the crisis,' NATO chief says
Russian president's spokesman believes German chancellor should carefully watch what she says on the Syrian crisis
With the latest advances, Ramadi and all its surrounding areas have been retaken from ISIL, opening a road to capital Baghdad
EU energy commissioner says the aim of the proposals 'is simple: to prevent and mitigate possible security of gas supply crises'
Lyutvi Mestan's new party to be called the Democrats for Responsibility, Freedom and Tolerance, abbreviated 'DOST' in Bulgarian
The cause of the accident near Bad Aibling, around 60 kilometres southeast of Munich, is not immediately clear
The country's bombing mission against ISIL in Iraq and Syria is set to end by February 22
A stable Libya is in the interests of the whole of the Maghreb and the whole of Europe,' European Parliament chief says
Human Rights Watch urges US president to call for ‘dismissal of politically motivated charges’ against former opposition leader when he meets Malaysian PM next week
Greece cannot protect Europe, new line of defense should be established at borders with Greece, says Hungarian PM
Turkish Republic of Northern Cyprus president says he wants to see Cyprus adopt two-zone federal structure