RIYADH (AFP) – Six Al-Qaeda militants who attacked a Saudi border point with Yemen last week killing five security officers on both sides were all Saudi nationals, the Saudi interior ministry said Tuesday.

Five of the gunmen were killed in the confrontation with security forces, including two who blew themselves up, while a sixth was wounded and arrested.

The ministry named the culprits, saying they were “all wanted Saudis” who were identified through DNA tests and that four of the gunmen had done time in jail, according to a statement carried by SPA state news agency.

The ministry had said that the militants attacked the Wadia border post in the south of the kingdom on Friday, an operation claimed by Al-Qaeda in the Arabian Peninsula.

The crossing is in Yemen’s southeastern province of Hadramawt, whose rugged terrain provides hideouts for AQAP militants.

AQAP, born in 2009 of a fusion of the Saudi and Yemeni branches of Al-Qaeda, is considered by Washington to be the jihadist network’s most dangerous affiliate.

To counter illegal crossings and arms smuggling, Saudi Arabia is building a three-metre (10-foot) high fence along its southern frontier.

Taking advantage of a collapse of central authority during a 2011 uprising that forced Yemen’s veteran strongman Ali Abdullah Saleh from power, Al-Qaeda seized swathes of the country’s south and east.

Saudi Arabia launched a massive crackdown on Al-Qaeda following a spate of deadly attacks in the kingdom from 2003-2006.