Madagascar's political crisis is likely to turn increasingly violent as frustrated supporters of the island's two rival leaders resort to war tactics to break the deadlock, analysts said this week. The vast Indian Ocean island off southeast Africa is divided between two presidents, two cabinets and a split military. Self-declared President Marc Ravalomanana, who says he won December elections but was cheated out of victory by vote rigging, controls the capital. Veteran President Didier Ratsiraka, who says no one won the poll and wants a second round of voting, retains considerable support in the provinces.