MOGADISHU (Reuters) - Somalia’s al Shabaab Islamist group said on Sunday it had captured some Kenyan soldiers during an attack last week on military bases in western Somalia near the Kenyan border.

The group, which did not say how many soldiers were held after Friday’s assault in Ceel Cadde, also said in a statement that more than 100 Kenyan soldiers were killed, revising up the number from the more than the 63 dead it had previously claimed.

Kenya has not given casualty figures beyond saying both sides sustained casualties. But a top Kenyan commander said on Sunday the army was conducting “search and rescue” operations without specifically saying if those it was looking for were captured.

“Mujahideen fighters ... stormed the Kenyan base in the early hours of Friday morning, killing more than 100 Kenyan invaders, seizing their weapons and military vehicles and even capturing Kenyan soldiers alive,” al Shabaab said in a statement.

The African Union’s AMISOM force, which includes Kenyans, along with Somali troops have driven al Shabaab from major strongholds in Somalia in a wave of offensives.

But the group still controls some rural areas and frequently launches attacks saying it wants to drive out the “invaders”.

Kenyan Defence Minister Raychelle Omamo said Kenya was striking back and would pursue the attackers. She spoke to reporters at a Nairobi airport where four wounded soldiers arrived back for treatment.

“This attack will not rest unanswered,” she said. “We have engaged the perpetrators decisively and remain in full pursuit of them.”

General Samson Mwathethe, chief of the defense forces, said Friday’s attack struck the Somali National Army base and an AMISOM base that was located in the same place. The attackers used vehicles packed with explosives and suicide bombers.

The minister said the attack was launched against a company-size force of soldiers, without making clear if this was the size of the Kenyan contingent in the area or the mixed force. A military company can range between 80 to 250 soldiers.

“Our priority now is to make sure that we conduct the search, rescue and recovery for the ones who are not in the camp but are elsewhere. We are trying to search for them, rescue them and recover them,” Mwathethe said without saying if they were captured.

The general said he would not release details for security reasons. “We have engaged the enemy and severely degraded him,” he added.

Al Shabaab often cites higher figures for death tolls than those given by officials, who usually play down the numbers. There was no independent death toll.

Al Shabaab said the attack was in retaliation for the Kenyan “invasion of Muslim lands”.

President Uhuru Kenyatta has repeatedly said he would not be coerced into withdrawing Kenyan forces from Somalia, saying the troops are protecting Kenya.