"The raids ... killed two leading al-Qaeda elements who were planning terrorist operations against vital installations in Yemen," an official said in a statement.

Jamil Nasser Abdullah al-Anbari, 25, who figured on a list of wanted fighters, was one of two al-Qaeda leaders killed in late Sunday's attack, an official told the AFP news agency.

Local residents told the Reuters news agency that as many as 20 civilians may have been killed in those attacks.

Targeting al-Qaeda

The Yemeni government has stepped up its attacks on suspected al-Qaeda positions in the country after the group claimed responsibility for a failed attack on a US airliner on December 25 last year.

Earlier this month, security officials said 11 men were arrested in the Yemeni capital, Sanaa, on suspicion of plotting attacks for al-Qaeda.

Al-Qaeda fighters have previously targeted Western embassies in the city.

On February 17, security forces arrested three suspected members of al-Qaeda in Marib province, east of the capital and on January 16, the authorities announced the arrest of three other suspected al-Qaeda fighters.

The previous day, an air raid killed six al-Qaeda leaders, including the group's top commander in Yemen, Qassem al-Rimi, according to officials.

And two days before, a Yemeni official said security forces killed Abdullah Mehdar, an al-Qaeda leader in Shabwa province in the east.

Last month General David Petraeus, the head of US Central Command, named Yemen as an area of the Middle East where he said al-Qaeda remains a growing threat.

Washington has reportedly supplied Yemen with intelligence and other support in its operations against al-Qaeda.

In January, a group of Yemeni religious leaders called for a holy war, if the US undertook direct military intervention.

But Barack Obama, the US president, has said he has "no intention" of sending in troops.