An improvised bomb exploded outside the republican palace in the Yemeni capital Sanaa on Saturday and wounded three Shi'ite Muslim militiamen guarding it, eyewitnesses said.
The attack came a day after the Houthi Shi'ite militant group dissolved parliament and formally took power of the impoverished and strife-town Arabian Peninsula country.
Once the home of the resigned Yemeni prime minister, the republican palace now houses Mohammed al-Houthi, a top official in the Iranian-backed movement's military wing whose gunmen now hold sway over much of Yemen.
There was no immediate claim of responsibility for the bomb But Sunni Muslim militants in al Qaeda in the Arabian Peninsula (AQAP) have repeatedly bombed and clashed with the Houthis, raising fears of a slide towards all-out sectarian conflict.
Also on Saturday morning, Houthi gunmen fired in the air to disperse dozens of people protesting against the movement's actions near Sanaa's main university.
The Houthis entered Sanaa in September and began to fan out into more cities in Yemen's south and west. Armed Houthi personnel were out in force after their Friday announcement, manning checkpoints around key government buildings.
Yemen has been in political limbo since President Abd-Rabbu Mansour Hadi and the government of Prime Minister Khaled Bahah resigned last month after the Houthis seized the presidential palace and confined the head of state to his residence in a struggle to tighten control over the country.
The United States and Yemen's energy-rich Gulf neighbours fear the breakdown in stability there might strengthen AQAP and unravel an international plan for a transition to democracy that has struggled to take hold since Arab Spring protests ousted Hadi's predecessor, veteran autocrat Ali Abdullah Saleh.
"The unilateral declaration issued today by the Houthis does not meet the standard of a consensus-based solution to Yemen’s political crisis," U.S. State Department spokeswoman Marie Harf told reporters on Friday.
