Hundreds of raucous supporters celebrated the return of firebrand Iraqi cleric Muqtada al-Sadr Thursday after his emergence from four years of exile in Iran, drawing a plea from him to show more discipline and restraint.

The populist whose militiamen once battled American and Iraqi forces left Iraq in 2007. Then, he was seen as a powerful but unpredictable leader of a street-fighting organization. Upon his return Wednesday, he was a legitimate political figure heading an organized movement that is a key partner in Prime Minister Nouri al-Maliki's new government.

The first public statement from him since his return, issued by his office Thursday, seemed designed to reinforce that image.

"I have seen only love and loyalty from you and this is exactly what you have seen from me, but the lack of discipline displayed by some of you, while I was performing my religious rituals and public matters, has bothered and harmed me. I demand you to exercise discipline," he said.

He was referring to the rapturous reception by hundreds of followers a day earlier, while he visited a holy shrine. Crowds chanted, "Muqtada is our only leader." Officials from his office said the cleric felt other politicians might view those cries as provocative.

Al-Sadr made no public appearances. According to his office in Najaf, al-Sadr will give a speech on Saturday although there was no information on where the speech would be delivered.

A swarm of al-Sadr's bodyguards — dressed in black clothes and flak jackets and armed with automatic rifles — deployed around his house in the al-Hanana neighborhood in central Najaf where followers were waiting to meet him.

One of the youngest among those gathered outside al-Sadr's house was 9-year-old Mohammed Sadiq, who was accompanied by his uncle. "I'd like to kiss his hands and tell him: 'I miss you and don't leave us again,'" said Sadiq.

Supporters hung banners on nearby buildings. One of them read: "Yes, yes to our leader. Here we are at your service our master Muqtada." Another banner said: "We renew our allegiance to our leader Muqtada al-Sadr."

The cleric was believed to be meeting with Iraq's most revered Shiite figure, Grand Ayatollah Ali al-Sistani, on Thursday but the meeting could not be confirmed.

Many Iraqi politicians could not be reached for comment Thursday, indicating the sensitivity that is felt in Iraq about the return of one of the country's most powerful and unpredictable politicians.

Al-Sadr has legions of followers among Iraq's downtrodden Shiite masses who see him as a champion of their rights against both the Sunnis who dominated Iraq under Saddam Hussein and other Shiite political parties such as al-Maliki's Dawa party, which represents more of the Shiite middle class.

Al-Sadr had not been seen publicly in Iraq since 2007. He left to study Islam in Qom, Iran, the seat of Shiite education. The sojourn was a way for the 37-year-old cleric to burnish his theological credentials at a time when he was sometimes criticized within Shiite religious circles for his relative religious inexperience. But he also faced an arrest warrant for his alleged role in assassinating a rival Shiite cleric.

The arrest warrant appeared to be in effect as recently as last March but the chances it would be enforced seem almost nonexistent considering the alliance between al-Maliki and al-Sadr. The public nature of al-Sadr's return — his first appearance in Iraq since leaving for Iran — suggested he had little to fear.

While al-Sadr's homecoming was a cause for joy among his supporters, his return caused trepidation among many Iraqis, particularly Sunnis who remember vividly the sectarian killings carried out by his militia, the Mahdi Army, and believe he is a tool of Iran.