Madagascar's embattled President Andry Rajoelina has appointed an army general as the new prime minister in a bid to end youth-led protests against his rule.

He said the nation needed a premier "capable of restoring order and the people's trust" before naming Gen Ruphin Fortunat Zafisambo to the post.

Coming days after the president expressed fears of a coup attempt, the general's appointment marks a significant militarisation of the government and appears to be an attempt by Rajoelina to secure the army's backing at a time of heightened tensions.

The protest movement, known as Gen Z Mada, rejected Gen Zafisambo's appointment, and gave Rajoelina 48 hours to resign.

"As long as Rajoelina remains in power we will continue the struggle," Gen Z Mada said in a statement.