"The revolution of Imam Hussein, peace be upon him, was and will remain the revolution of freedom and justice in the face injustice and tyranny,” said Iraqi President Barham Salih in a statement extended condolences to the country.
"It is also the revolution of reform and changing reality. It is also the homeland of seekers of humanity, life, and social justice,” he said.
"Hussein, peace be upon him, went out to demand reform in this ummah [community]. So let our slogan, work, and efforts be focused towards purging our countries from corruption, mismanagement and deprivation of services and rights."
Arbaeen, meaning 40, is a holy day for Shiites. It marks the 40th day following the killing of Imam Hussein, a revered Imam and beloved grandson of the Prophet Mohammed. He was killed by rival Islamic forces.
On this day, according to accounts, his sister Zaynab, herself a revered figure for Shiites, his son Ali Bin Hussein, and other children and companions, visited Imam Hussein’s grave in Karbala, present-day Iraq.
Today, millions of faithful people from Iran, Afghanistan, and around the world visit Karbala, some 85 kilometres southwest of Baghdad.
The prime minister of the Kurdistan Regional Government also sent a message, saying the day was one for patience and steadfastness for those wishing to leave a mark on history and the struggle for rights.
“We hope the commemoration ceremony will proceed forth peacefully and hope it will be a motivation to uplift injustice, eliminate corruption, and to seek security, co-existence, sharing and for all owners of rights to obtain their rights,” PM Nechirvan Barzani tweeted on Tuesday.
Visitors to Karbala echoed the spirit of reform.
"We call for unity because Imam Hussein calls for us to be united. And Imam Hussein went out for reform. So we call on the current newly-elected Iraqi government to do reforms and eliminate corruption. Providing services is the most important things for citizens,” said a visitor.
Iraq ranks among the most corrupt nations in the world. Public anger over corruption and lack of government services were driving factors behind frequent protests in Baghdad and the south of the country, including deadly demonstrations in Basra this summer.
According to official figures, tabulated from cameras on the main gates of Karbala, 11,853,487 people had visited as of Tuesday afternoon. This number does not include visitors who enter from alleys and secondary streets.
Security is tight as the Sunni militant group ISIS remains a terror threat in Iraq. The Ministry of Defense announced on Monday that it had foiled an ISIS suicide attack targeting at Arbaeen visitors.
Two people were killed in a bombing in Khanaqin earlier on Tuesday.
Iraq’s Prime Minister Adil Abdul-Mahdi visited Karbala where he met with local and federal officials, including deputy head of the Hashd al-Shaabi Abu Mahdi al-Muhandis, to “check out the security and services reality,” according to a readout from his office.
