Nairobi - Kenyan police have arrested 13 members of an outlawed separatist movement and accused them of planning ethnically-motivated attacks similar to assaults that killed dozens in the coastal region this month, the Interior Ministry said.
About 65 people died in back-to-back attacks in the coastal town of Mpeketoni. Somalia's al-Shabaab Islamist group claimed responsibility, but President Uhuru Kenyatta dismissed that and blamed local groups.
The two Mpeketoni assaults in mid-June were followed by a raid that killed five in another town in the region on Monday.
The Interior Ministry, on its Twitter site, said the 13 people arrested were members of the banned Mombasa Republican Council, which wants the coastal region to secede from the rest of Kenya.
It has denied any role in the Mpeketoni attacks and there was no immediate comment from the group after the detentions.
"The 13 arrested by police are suspected to be planning to attack four areas - Witu, Kipini, Marereni and Garsen - all in the coastal region," the ministry said, saying they had planned an "ethnic cleansing attack similar to Mpeketoni".
Last week, officials said security forces killed five of the suspected Mpeketoni attackers. Police said they had not established their identities and no one had collected the bodies.
Al-Shabaab gunmen attacked an shopping mall in the capital in September, leaving at least 67 people dead.
Many Kenyans accuse the government of failing to do enough to prevent such violence.
Rights groups say the police often use heavy-handed tactics, such as mass round ups of Somalis or Kenyans with Somali links, only to free most of them. The groups say this deepens resentment in the community.