Al Qaeda militants escape from prison in Yemen: At least 40 inmates are on the loose

Nearly 60 al-Qaeda militants made a daring prison escape in Yemen Wednesday, overpowering their guards and disappearing into the increasingly lawless countryside.

In a carefully choreographed escape, 57 militant prisoners seized their guards' weapons and crawled out an underground tunnel as bands of heavily armed attackers struck the prison in Mukalla on the Arabian Sea.

One guard was killed and another wounded in the attack, officials said.

Some of the escapees were militants convicted on terror charges or those being held in protective custody pending trial, officials confirmed.

It was the most alarming prison escape by al-Qaeda thugs in Yemen since 2006, when 23 escaped a detention facility in the capital of Sanaa.

Among them was Qassim al-Raimi, who has become the dominant figure in al-Qaeda's deadly Yemeni branch, which has been linked to several attempted attacks on U.S. targets, including a plot to bomb a Detroit-bound airliner in December 2009.

The group also put sophisticated bombs into UPS packages that made it onto cargo flights.

Yemen's political crisis has opened the door for increasing freedom for militants to operate.

After months of violent demonstrations, Yemen's president of more than 30 years left the country for treatment after being badly wounded in an attack on the palace.

Since his departure, President Ali Abdullah Saleh's vice president has been in charge.