* Strikes in south kill 25 suspected al Qaeda members
* Ten militants, three civilians killed a day earlier
* Govt says attacks were planned on 'vital installations' (Adds U.S. Congressman's quotes)
By Mohamed Mukhashaf
ADEN, Yemen, April 20 (Reuters) - Air strikes in southern Yemen killed about 25 suspected al Qaeda members on Sunday, local tribal sources said, in the second operation of its kind within two days.
On Saturday an air strike killed 10 al Qaeda militants and three civilians in central Yemen, a country that neighbours top oil exporter Saudi Arabia and is home to al Qaeda in the Arabian Peninsula (AQAP), one of the group's most lethal wings.
The defence ministry said Sunday's strikes targeted a remote mountainous region of the south. Its website quoted an official source on the High Security Committee as saying that they were based on information that "terrorist elements were planning to target vital civilian and military installations".
Similar wording was used to justify Saturday's strike, in which three nearby civilians were also killed.
The defence ministry did not specify the nature of the air strikes, but in both cases local sources said unmanned drone aircraft had been seen above the target areas beforehand.
The United States acknowledges using drone strikes to target AQAP in Yemen, but it does not comment on the practice.
Local tribal sources said about 25 bodies had been transferred from the sites of Sunday's attacks to nearby towns. They said at least three separate strikes had taken place after dawn prayers, all targeting al Qaeda camps.
One official said the militants targeted were among the "leading and dangerous" elements of al Qaeda and were of different nationalities.
Eyewitnesses said they had seen al Qaeda militants dragging dead bodies and some wounded people out of the area.
AQAP TOUGH TO BEAT
U.S. drone attacks have killed several suspected AQAP figures, including, in 2011, Anwar al-Awlaki, a U.S.-born Islamist cleric accused of links to the attempted bombing of a Detroit-bound airliner in 2009 and U.S. cargo planes in 2010.
U.S. congressman Michael McCaul of Texas, the chairman of the U.S. House of Representatives Committee on Homeland Security, said AQAP posed "probably the greatest external threat to the homeland itself".
"And so I think the fact the administration now is going aggressively against these terrorists ... is a very positive sign," said McCaul, appearing on the Sunday morning ABC News programme "This Week".
U.S. officials credit the drone strategy for the fact that AQAP is no longer able to control territory in Yemen as it did in 2011. But critics, including some Yemenis and U.S. politicians, say the strikes and civilian casualties are increasing sympathy for AQAP and resentment against America.
Saudi Arabia also watches AQAP with concern, since the branch was founded by citizens of both countries and has sworn to bring down its ruling al-Saud family.
An online video has been circulating with AQAP leader Nasser al-Wuhaishi addressing a large gathering of fighters in an undisclosed mountainous region of Yemen and vowing to attack the United States.
Yemen has been fighting AQAP but the group, which has attacked military targets, tourists and diplomats in the country and taken over territory for long periods, is proving hard to defeat. (Additional reporting by Jim Loney in Washington; Writing by Yara Bayoumy and Maha El Dahan; Editing by Mark Trevelyan)