Al-Shabab fighters claim they killed at least 15 people in a second night of attacks on Kenya's coast, but the country's president says the attacks were the work of "local political networks" and gangs.

The latest attack happened overnight on Tuesday in Pomoroko, a village located between the city of Mombasa and the Kenyan border with Somalia, where the armed group is based.

The attack come after 48 people were killed in Mpeketoni in the early hours of Sunday. Al-Shabab claimed they carried out the attack to punish the Kenyan government for sending troops to Somalia.

However, President Uhuru Kenyatta denied al-Shabab's role in the attacks, instead blaming what he called "local political networks" and criminal gangs.