Prime Minister Thomas Thabane is under pressure to step down after police said they suspect him of having a hand in the murder of his estranged wife in 2017.

In an address on public television the 80-year-old Thabane said he had "deployed the army to take control of this situation and take necessary measures against these elements in alignment with the security orders and restore peace and order".

"This is to avoid putting the nation in danger," he said.

A highly placed government source said police commissioner Holomo Molibeli, his deputy Paseka Mokete and another senior police officer, have been arrested by the army.

"The general informed the prime minister that he has arrested Holomo, Mokete... They are temporarily detained at Makoanyane Barracks," the source told AFP in the capital Maseru.

There was a heavy presence of armed soldiers, in bulletproof vests and helmets, patrolling the streets.

Other soldiers drove around Maseru in armoured cars.

The prime minister's order is the latest twist in a saga that has gripped the southern African kingdom.

The police accusations against him came after communications records from the scene of his estranged wife's murder included Thabane's mobile phone number.

His order deploying the army comes a day after the constitutional court set aside his decision to suspend parliament for three months.

Thabane suspended parliament last month shortly after the national assembly passed a bill barring him from calling fresh elections in an event he losses a no-confidence vote hanging over his head.

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