Sadr, a politician whose list won the 2018 legislative elections, helped Prime Minister Adel Abdel Mahdi form his government later that year.

But as the death toll rose in protests that rocked Iraq earlier this month, Sadr called on Adel Mahdi to resign and threatened to mobilise his supporters.

The official count puts the number of dead at 110, the vast majority protestors killed by live fire during the demonstrations against chronic corruption and unemployment.

On Twitter, Sadr called Tuesday evening for "Iraqis on the move" toward Karbala for the Arbaeen pilgrimage "to mobilise by the millions".

"March draped in your shrouds... and chant on Arbaeen: No to America! No to Israel! No to the corrupt!" Sadr wrote.

The commemoration marks the end of a period of mourning for Imam Hussein, a founding figure in Shiite Islam.

The annual Arbaaen pilgrimage sees millions of worshippers, mostly Iraqis and Iranians, converge by foot on Karbala, 100 kilometres (60 miles) south of Baghdad.

Placards with anti-United States and anti-Israel messages are often seen in the crowd, though anti-corruption slogans are rare.

Last year, more than 15 million worshippers participated in the gathering, which is always held under tight security, as Sunni jihadists have in the past targeted Shiite pilgrims.

bur/sw/par

Twitter