Indian military says suspected rebels from the Naga tribe in northeastern Manipur state have ambushed an army convoy, killing at least two soldiers and seriously wounding at least two others. The military says heavily armed militants attacked the convoy early Sunday southeast of Imphal, the state capital. The incident follows a day of rioting by protesters from the Naga tribal group in four Manipur districts, during which they set ablaze government buildings. The riots began after Indian soldiers fired shots to disperse the crowds, wounding at least two protesters. Some Naga tribal groups want to integrate Naga-inhabited areas in Manipur into a single tribal state. Naga separatist leaders and New Delhi signed a cease-fire in 1997. It followed decades of violence that killed more than 20,000 people.