A Kenya military plane has crashed in southern Somalia, the army said, citing "technical problems" while Somalia's al-Shabab fighters claimed they had shot it down.

There are reports that the pilot is dead and two members of the crew are missing after Thursday's incident.

Al Jazeera's Catherine Soi, reporting from Nairobi, said that the jet came down at around 3:15pm local time, according to a military spokesperson.

In a statement, Colonel David Obonyo said the warplane "while returning from a combat mission in Jamaame, southern Somalia, developed technical problems and crashed in the general area of Kismayo".

However, a spokesperson from al-Shabab told Al Jazeera that the group had shot down the fighter jet.

"There is a big propaganda war going on from both sides," said our correspondent

She added that there were no photos or evidence to back either side's claims.

Kenyan troops entered southern Somalia three years ago to fight the al-Qaeda-affiliated rebels, later joining an African Union peacekeeping force.

They have carried out heavy airstrikes on al-Shabab bases in southern Somalia after the armed group carried out a string of attacks inside Kenya, including two recent massacres of over 60 people.

Uhuru Kenyatta, the Kenyan president, has vowed to "intensify the war on terrorism", calling al-Shabab fighters "deranged animals" and blaming them for the death of more than 800 Kenyans.

Al-Shabab in turn warned they would be "uncompromising, relentless and ruthless" in further attacks. 

Source: Al Jazeera and agencies