Kenya says other foreign military forces have joined an offensive against al-Shabaab militants in Somalia.

Military spokesman Emmanuel Chirchir said Sunday that a French naval ship bombed the southern Somali town of Kuday near the rebel stronghold Kismayo.

Warplanes have also carried out airstrikes in recent days in Kismayo, but it is not clear who was responsible for the attacks.

Chirchir said the airstrikes were done by allies, but no other nations, including France or the United States, have confirmed any involvement in the operation in Somalia.

Kenya sent its troops into Somalia earlier this month to pursue militants it blames for a string of foreign kidnappings on Kenyan soil, threatening the country's reputation as a safe investment and tourist destination.