Aden - Two men were killed in southern Yemen when a bomb they planned to use in an attack on government forces exploded accidentally late on Saturday, the Interior Ministry said in a statement.

“The bodies of the two were ripped apart in the explosion, which happened before they were able to execute their attack,” the ministry said in the statement posted on its website.

Yemeni security forces, fighting a growing Islamist insurgency, said they had also detained four Somali men suspected of belonging to the al Shabaab militant group near the site of the explosion. There was no indication that they were linked to the bomb plot, the statement said.

The al Qaeda-allied Somali group had sent 300 armed men to fight alongside the Yemen-based wing of the militant network, it said. The four Somalis were captured on the road between the southern provinces of Lahej and Abyan.

The two dead men were identified by the ministry as Yasser and Muneef al-Hawi. The statement said they were killed in Abyan province's Mudiyah district.

It gave no further details on whether the men were associated with al Qaeda.

U.S. drone attacks killed at least 25 al Qaeda-linked fighters in Yemen on Saturday, while a Yemeni air force raid killed 20 more, also in the south, where militants have expanded their operations during a year of unrest that ousted former President Ali Abdullah Saleh.

Saturday's operation was the biggest since Yemen's President Abd-Rabbu Mansour Hadi, elected in February, promised in his inauguration speech to make fighting al Qaeda a priority.

The United States and Saudi Arabia, Yemen's neighbour and the world's biggest oil exporter, are concerned about al Qaeda's expansion in Yemen where the group controls swathes of land near oil shipping routes through the Red Sea. - Reuters