ISLAMABAD, May 10 (Reuters) - Pakistan's government called in the army on Wednesday (May 10) to help end deadly unrest in the wake of the arrest of former prime minister Imran Khan, warning protesters against any further attacks on state installations.

At least five people have died in violence that has aggravated instability in the South Asian country of 220 million people as it grapples with a severe economic crisis and a delay to an International Monetary Fund bailout since November.

Khan - Pakistan's most popular political leader according to polls - was arrested in a land fraud case on Tuesday, prompting supporters to storm military buildings and ransack the residence of a top army general in the eastern city of Lahore.

Other state buildings and assets have been attacked and set ablaze by protesters, and the government said on Wednesday it had approved requests from two of Pakistan's four provinces - Punjab and Khyber Pakhtunkhwa, both Khan strongholds - and the federal capital Islamabad to deploy troops to restore order.

The army issued a statement saying it had shown restraint during earlier violence but any further assaults on the military or law enforcement agencies, state installations and properties "will be met with severe retaliation".

UN Secretary-General Antonio Guterres wants all parties in Pakistan to refrain from violence and stresses the need to respect the right to peaceful assembly, deputy UN spokesperson Farhan Haq said in New York on Wednesday.

Guterres had also urged Pakistani authorities to "respect due process and the rule of law in proceedings" against Khan.