Suspected al-Qaeda militants have blown up an oil pipeline in Yemen.

Yemen's army deployed to the south of the country, where insurgents attacked a pipeline run by Korea National Oil Corp, shutting output from a 10,000 barrels-per-day field in Shabwa province.

The aim of the military operation in the provinces of Maarib and Shabwa, where oil and gas fields of international companies are located, was to capture suspected bomb maker Ibrahim al-Asiri, a Yemeni security official said.

The mission is also to catch the US-born radical Muslim preacher Anwar al-Awlaki, who is wanted by Washington.

Yemeni President Ali Abdullah Saleh has urged US President Barack Obama to intercede with European countries to drop bans on passenger or cargo flights from Yemen, which they imposed after the security scare.

He said: "The decisions by some European countries to stop flights from Yemen is a collective punishment for the Yemeni people."

Yemeni authorities also began the trial in absentia of Awlaki, who has been linked to the failed bombing of a US-bound plane in December 2009 that was claimed by Yemen's al-Qaeda wing and who is thought to be in southern Yemen.