Yemeni troops Saturday shot dead five Al-Qaeda suspects disguised as women who fired at a soldier during a checkpoint inspection of their Saudi-bound bus, officials said.
Another suspect and the driver were wounded in the shooting in Harad, a town 15 kilometres (nine miles) from the Saudi border, the officials said, adding that two of those killed were Saudis.
"As one of the soldiers climbed on board the bus for an inspection, one of the suspects opened fire and wounded him, prompting shooting from other soldiers at the checkpoint," said a government official who gave the toll.
All six had been dressed in black robes and wore the niqab, a face-covering veil commonly worn by women in Yemen, the official in Harad told AFP.
A suicide belt and arms were also found on the bus, and the wounded suspect and driver were being questioned, said the security official.
"The men are suspected of affiliation with Al-Qaeda and were heading north towards Yemen's border with Saudi Arabia," he said.
Yemen security forces rarely carry out inspections of vehicles carrying women in the conservative, deeply-tribal Muslim country.
In July, six Saudi Al-Qaeda suspects attacked a post on the border with Yemen, killing five security officers.
Al-Qaeda in the Arabian Peninsula took advantage of a collapse of central authority in the wake of the 2011 uprising to seize swathes of southern and eastern Yemen.
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The United States considers AQAP to be the global jihadist network's most dangerous affiliate.
Saudi Arabia, which launched a huge crackdown on Al-Qaeda following a spate of deadly attacks in 2003-2006, is building a three-metre (10-foot) high fence along its southern frontier with Yemen to counter illegal crossings and arms smuggling.
Yemen has been wracked by violence since a Shiite militia known as the Huthis seized control of the capital in September.
The militiamen have clashed with local Sunni tribes and Al-Qaeda militants as they seek to expand their territory.
Several Huthi militiamen were killed and 10 tribesmen wounded in fighting Friday in Arhab, 35 kilometres (20 miles) from Sanaa, according to sources on both sides.
Arhab is close to Sanaa International Airport and is a stronghold of the Sunni Islamist Al-Islah party.
Later on Saturday, tribal sources said armed tribesmen handed Arhab over to the Huthis following mediation that led to an end of fighting.
In Sanaa, hundreds protested outside President Abdrabuh Mansur Hadi's residence demanding action against the militiamen, whom they accused of arrests and killings.
"Huthis and Al-Qaeda are the same. Hadi, either find a solution (to end their control) or leave."
The rise of the Huthis has challenged Hadi's authority, an ally of the United States, and violence has continued despite UN-backed efforts to find a political solution.