NAIROBI (AFP) -- Kenya's top Muslim leaders warned Tuesday that Islamist attacks and a harsh government response risked dividing the country along ethnic and religious lines that could trigger a repeat of the deadly post-election violence six years ago.

"The continued violence risks tearing the country apart ... while little has come from the government to address these concerns," Abdullahi Abdi, chairman of the National Muslim Leaders Forum, told reporters.

At least 15 people were reported to have been killed Tuesday in a new attack near Kenya's coast, a day after Somalia's Al-Qaeda-linked Shebab rebels massacred close to 50 people in the same area.

"Some of these attacks are aimed at planting seeds of discord and animosity among Kenyans and (to) divide the country along ethnic and religious lines,"said Sheikh Mohammad Khalifa, of the Council of Imams and Preachers.

The situation is "a recipe for sectarian and ethnic violence which might be a repeat of the tragic events of 2007," he added.

Heavy handed police operations on the coast -- with Muslim communities accusing the government or extra-judicial killings of radical clerics -- have enraged many, as have the round-ups in the capital of ethnic Somalis and Somali refugees.