Yemen's president replaced security officials and some ministers late on Tuesday, state media reported, in an apparent move to reduce the influence of former leader Ali Abdullah Saleh following an attempt on the defence minister's life.
A car bomb targeting the motorcade of Defence Minister Major General Muhammad Nasir Ahmad in Sanaa on Tuesday killed 12 people and wounded dozens but left him largely unscathed.
Yemen has been in turmoil since an uprising against Saleh last year that forced the former president to step down in November under a Gulf power transfer deal in favour of his deputy, Abd-Rabbu Mansour Hadi.
Hadi appointed a new oil and minerals minister, Ahmed Dares, and higher education minister, Hesham Sharaf, state news agency Saba said. He also replaced the heads of military intelligence and national security, both seen as close to Saleh, and appointed two officials to key posts in the president's office.
The new military intelligence chief, Ahmed al-Yafie, was formerly a senior defence ministry official. Incoming national security chief Ali Hassan al-Ahmadi was previously governor of Shabwa province in southern Yemen.
Hadi's new presidential office manager Nasr Taha Mustafa was formerly the chief of the state news agency who turned against Saleh during last year's uprising.
Saba also said the position of secretary general of the president's office was now held by Ali Mansour bin Safaa, former ambassador to Bahrain who hails from Hadi's region of Abyan in southern Yemen.
"This was expected. They are the demands of youth and political circles to complete the process of transferring authority and distancing some power centres who have a strong connection to the tension and current events," Ali al-Sarari, a government advisor, told al-Jazeera television.
Thousands of Yemenis marched through Sanaa on Tuesday to demand Saleh be tried over corruption and the deaths of protesters. They denounced the U.S.- and Saudi-backed power transfer deal that gave him immunity from prosecution for standing down.
Hadi has been trying to assert his authority over the military, locked in a war against al Qaeda militants who took advantage of the unrest to seize territory in the south.
He has already sacked the air force chief, a brother of Saleh. He has also set up a new force under his command composed of units from the Republican Guards, a force led by Saleh's son Ahmed, and units of a dissident general, Ali Mohsen, who broke with Saleh last year.
While the army ousted al Qaeda and its allies from areas of the south this year, militants have staged a series of suicide attacks against military facilities and officials.
The lawlessness has alarmed the United States and Yemen's neighbour Saudi Arabia, the world's top oil exporter, which view the impoverished state as a front line in their war on al Qaeda and its affiliates.