Yemen said on Monday its security forces had foiled a planned al Qaeda attack in the southern province of Aden.
The announcement came three days after a suicide bomber killed four soldiers and a civilian and wounded 16 people in Aden. A local newspaper said on Monday that investigators had identified the suicide bomber as a Saudi national.
Yemen's state news agency Saba quoted a security source as saying six people "among some of the most dangerous elements" of al Qaeda were captured while trying to infiltrate into the province, which includes a port and oil refinery.
The report described the intended target of the thwarted attack as "vital and economic installations", giving no further details.
Months of popular protests demanding President Ali Abdullah Saleh end his 33 years in power have brought near chaos to Yemen, which is home to al Qaeda's potent regional wing and also faces a separatist revolt in its south and a tenuous peace with Shi'ite rebels in its north.
The Yemeni army has been battling hundreds of Islamist militants affiliated to al Qaeda who seized control of the southern city of Zinjibar and smaller towns in the province of Abyan. The United States and Saudi Arabia fear that al Qaeda will exploit the country's chaos to launch attacks.
The security source said the arrested militants, all bomb experts, were carrying detonators and wireless communications equipment.
The state news agency, which frequently plays up the threat from al Qaeda, gave no further details and the report could not be independently verified.
Saba said five al Qaeda militants had been killed and seven Yemeni soldiers were injured in clashes in Abyan.
A local Yemeni official, reporting on fighting in the same area, said three militants were killed and five were captured. The official said one soldier was killed and two were wounded.
Opponents of Saleh say the president let his forces hand over control of Zinjibar to militants in order to stoke fears that only his rule could prevent an Islamist takeover.