the details were added (the first version was posted at 12:00)
An air strike killed five al Qaeda militants in Yemen on Monday, state media said, as the army sent reinforcements to two regions in what appeared to be a further expansion of an offensive against the Islamist group, Reuters reported.
The attack destroyed a car carrying the militants in the Wadi Abida district of the northern province of Maarib, a military source and a local official told Reuters. Both had earlier said it was carried out by a drone.
The strike appeared to be the latest move in a U.S.-backed campaign to crush al Qaeda's Yemeni wing, al Qaeda in the Islamic Peninsula (AQAP), whose fighters who have mounted dozens of attacks on government officials, security forces and foreigners in recent months.
In a further sign of the deteriorating security situation, members of the presidential guard clashed with armed tribesmen in a car near the presidential palace in central Sanaa on Monday, a police source said. Residents reported hearing heavy gunfire in the area.
It was the third clash in that part of the city since Friday; police said it had occurred when the tribesmen rammed their way through a checkpoint.
The previous two incidents had been blamed on Islamist militants, and appeared part of a pattern of assaults aimed at signaling their resilience in the face of the government's offensive.
Al Qaeda and its allies have grown in strength in Yemen, taking advantage of the political turmoil following a mass uprising in 2011 that eventually overthrew the president.
The chaos has jeopardised a delicate transfer of power to an interim government, posed a threat to oil-producing neighbor Saudi Arabia and alarmed Western powers, who fear al Qaeda could launch international attacks from the impoverished country.
More special forces were on their way to Maarib, east of the capital Sanaa, and the central province of al-Bayda, military sources told Reuters.
Yemen's army says it has already killed dozens of militants since it stepped up its offensive against AQAP - regarded as one of al Qaeda's most lethal wings - two weeks ago.
A series of drone strikes in late April in al-Bayda and the southern provinces of Abyan and Shabwa killed at least 65 militants, said officials.
The United States has acknowledged using drones in Yemen, though it does not comment on individual strikes.
Revenge attacks blamed on Islamist militants have increased in the aftermath of the army campaign.
A suicide bomber rammed a car packed with explosives into a military police complex in the southern coastal city of Mukallah on Sunday, killing at least 11 soldiers.