Military helicopter crash kills 13

Sulaiman said military was suspecting that bad weather caused the crash.

He said Poso was the scene of deadly Muslim-Christian violence in 1999-2000, and the area has since become a known hotbed of militant activity.

Spokesman said last week police killed two suspected Islamist fighters from China's Uighur ethnic group in a gunfight in Poso as part of an operation to crush a group led by a wanted militant named Santoso.

Sulaiman said more than 2,500 military and police personnel have been deployed in the area since January.