Yemeni forces killed three suspected Al-Qaeda militants in a raid on their hideout in Aden, foiling a major plot to blow up targets in the restive southern port city, a security official said on Tuesday.

"We raided a house in the Mansoura district... clashes broke out, three Qaeda operatives were killed and four members of the security forces were wounded," said the official, who spoke on condition of anonymity.

Tuesday's operation "foiled several terror attacks that were going to be carried out in the coming hours," he added.

Two vehicles packed with explosives and three suicide belts were discovered at the hideout, the official said, without giving further details.

One of the operatives killed in the operation was a Somali national. A fourth Al-Qaeda suspect was arrested, the official added.

Al-Qaeda took advantage of the weakness of Yemen's central government in 2011 during mass protests against now ousted president Ali Abdullah Saleh to expand its presence in the east and south of the impoverished country.