* First major air strikes since October after mall attack
* Al Shabaab denies any casualties
* Residents say militants regrouping in the area
Kenya's military has killed more than 30 al Shabaab militants and commanders, a spokesman said, in its first major air strikes in Somalia since the retaliation for the Islamists' attack on a Nairobi shopping mall.
Kenyan fighter jets hit a camp at Garbarahey in the Gedo region on Thursday evening, where the militants, who profess links to al Qaeda, were holding a meeting, the military said.
Al Shabaab has been weakened by African Union troops over the past two years, ushering in some stability in many parts of the Horn of Africa country after a campaign of cross-border raids and kidnappings of Westerners and security forces.
However, the rebels, who have waged a seven-year insurgency seeking to impose a strict interpretation of sharia law in Somalia, stunned the world in September when they attacked an upscale shopping mall in Nairobi, killing at least 67 people.
Thursday's air raids were the first since October, when Kenyan warplanes bombed targets held by the Islamists in reprisal for the attack on the mall..
"There are remnants of al Shabaab that are still trying to draw back the gains that have been made (against them)," Kenyan military spokesman Colonel Cyrus Oguna told Reuters on Friday.
"Those remnants are the ones we are focusing on now."
Despite more than two years of attacks on al Shabaab positions by Kenyan and other east African troops, there is no clear picture of how many are involved in the movement or whether its numbers have been eroded by the intervention.
After October's raid, the Kenya Defence Forces said it destroyed a training camp, killing or wounding many of the more than 300 fighters there.
The militants, who said they attacked the shopping centre because of Kenya's intervention in Somalia, denied then there had been any attack and on Friday denied they had lost any men.
"No single fighter was killed in yesterday's air raid. The plane bombarded an empty place. Kenya's claim is their usual propaganda," sheikh Abdiasis Abu Musab, al Shabaab's spokesman for military operations, told Reuters.
It was not immediately clear what, if anything other than opportunity, had triggered Thursday's raids.
Residents in Gedo, however, said al Shabaab has been regrouping its fighters in the area over the past days.
"We heard several bombs targeted at Galweeyne which is a stronghold for al Shabaab," resident Nur Farah told Reuters from Garbarahey town.
Oguna said the strikes would continue, and would target the militants' support infrastructure including command centres, communication centres and their logistics bases.
"We keep on hunting them down and the moment we identify where they are, we hit them," Oguna said.
The profiles of the killed Shabaab commanders would be made public later, he said.