Kenyan troops killed 34 al Shabaab militants in two separate incidents on Saturday and Sunday in Somalia, a military spokesman said.

On Saturday, the Kenya Defence Forces (KDF) killed 21 of the insurgents in the southern town of Afmadow in the ambush in which the two soldiers died.

David Obonyo, spokesman for KDF, said in a statement that on Sunday, Kenyan troops killed a further 13 fighters just north of Ras Kamboni, also in southern Somalia.

"The KDF soldiers pursued them following information of an intended probe attack. Following the incident, a middle level al Shabaab commander has been detained, 13 militants were killed," Obonyo said, referring to a reconnoitre attack by al Shabaab.

"Regrettably, KDF suffered two fatalities and five injuries. The injured were evacuated and are receiving medical attention," he said of the incident on Saturday. An improvised explosive device also damaged one of the Kenyan army's vehicles, he said.

He said from the two incidents, KDF troops had recovered 27 AK 47 rifles, five rocket propelled grenades, a pistol, two PKM machine guns and ammunition.

Somalia's government is battling to rebuild the Horn of Africa nation after more than two decades of conflict. Al Shabaab ruled large parts of Somalia until 2011, when it was driven out of Mogadishu by African Union (AU) and Somali troops.

The militants, who aim to topple the Western-backed government, often inflate casualty numbers and downplay the number of their own fighters killed.

Abdiasis Abu Musab, al Shabaab's military operation spokesman, told Reuters on Saturday their fighters had killed 12 soldiers in the Afmadow attack.