BAGHDAD — Iraq's Shiite spiritual leader Grand Ayatollah Ali Sistani called on the government on Friday to heed the demands of protesters who have thronged Baghdad and other cities for four straight days and condemned the mounting death toll from clashes with police.

The endorsement from Sistani, who is revered among Iraq's Shiite majority community, prompted celebratory gunfire from protesters and piled new pressure on Prime Minister Adel Abdel Mahdi as he battles to quell the intensifying unrest.

Many had been waiting for a signal from Sistani in his Friday prayer sermon read out by representatives in Shiite holy places across Iraq before deciding whether to join other protesters in defying the daytime curfew in force in Baghdad and other cities.

The prime minister has appealed for patience from the young unemployed who have formed the mainstay of the protests, saying his not yet year-old government needs more time to implement reforms.

But Sistani retorted that the government needed to act now "before it's too late" to address popular grievances or the protests would simply intensify.

The crisis required "clear and practical steps" or the protesters will "simply come back even stronger", he said.

The government "must do what it can to improve public services, find work for the unemployed, end clientelism, deal with the corruption issue and send those implicated in it to prison", Sistani added, listing some of the protesters' main grievances.

Protests first broke out in Baghdad on Tuesday and have since spread across the Shiite-dominated south, while northern and western provinces that were ravaged in the 2014-2017 war against the Islamist State group have remained relatively quiet.

They are unusual because of their apparent spontaneity and independence in a country where rallies are typically called by politicians or religious figures.

Sistani voiced dismay at the mounting death toll.

"There are attacks on peaceful protesters and security forces which we reject and condemn," he said.

At least 36 people have been killed, including four police, since Tuesday, medical and security sources said.

Authorities in neighboring Iran have called on citizens planning to take part in a major Shiite pilgrimage in Iraq this month to delay their travel "until conditions ease".

Sistani's message is a huge blow to Abdel Mahdi's government. The top cleric has repeatedly acted as final arbiter of the politics of Iraq's Shiite community, which dominates the government.

In 2014, Sistani effectively put an end to the government of then prime minister Nuri Al-Maliki.

In his first public address since the protests erupted on Tuesday, Adel Mahdi had asked for more time to implement his reform agenda in a country plagued by corruption and unemployment after decades of conflict.

"There are no magic solutions," he said.

Riot police have unleashed water cannons, tear gas, rubber bullets and live fire to clear the streets of protesters, who amassed despite curfews and an internet blackout across three-quarters of Iraq since Wednesday.

But in his speech on Friday, Abdel Mahdi gave his full support to the security forces, insisting they were abiding by "international standards" in dealing with protesters.

He described the clashes as "the destruction of the state, the entire state", but refrained from directly addressing protesters' demands.

The United Nations and international human rights organizations have called on the government and the security forces to respect the right of peaceful assembly.

"We are worried by reports that security forces have used live ammunition and rubber bullets in some areas, and have also fired tear gas canisters directly at protesters," Marta Hurtado, spokeswoman for the UN human rights office, told reporters in Geneva.

Amnesty International echoed the criticism.

"It is outrageous that Iraqi security forces time and again deal with protesters with such brutality using lethal and unnecessary force," said Amnesty's Lynn Maalouf.

She said the internet blackout was a "draconian measure... to silence protests away from cameras and the world's eyes". — AFP