NAIROBI, Kenya — As Kenyan officials reported a second lethal attack on a coastal village, Kenya’s president said Tuesday that the violence, which has left at least 57 people dead, was the work of “local political networks” and was not carried out by the Shabab, a Muslim extremist group that has claimed responsibility.

“The attack in Lamu was well-planned, orchestrated and politically motivated ethnic violence against a Kenyan community,” said President Uhuru Kenyatta, addressing the nation and referring to the county where the attack occurred, which includes the Lamu Island tourist resort. He said the killings involved an eviction attempt but did not elaborate or provide evidence.

“This, therefore, was not an Al Shabab terrorist attack,” he said. “Evidence indicates local political networks were involved in the planning and execution of the heinous attacks. This also played into the opportunist network of other criminal gangs.”