Beating a small drum and walking through the streets of his neighbourhood in the early hours, Luay Sabbah shouts, "Suhoor! Suhoor!", plying a craft that is increasingly rare in Iraq.

The 20-something spends his pre-dawn hours, like his counterparts nationwide, waking neighbourhood residents for the meal that precedes a Muslim's daily fast during the holy month of Ramadan, known as the suhoor.

But he is among the few remaining men of his kind, known in formal Arabic as a mousaher and referred to in Iraq as a mousaherati, who walk the streets of neighbourhoods, clad in traditional dishdashas, waking Muslims so they can eat before the sun rises.

They have largely fallen victim to tough security measures implemented to combat the violence that erupted following the 2003 US-led invasion that ousted dictator Saddam Hussein.

Combined with longer-term trends such as improved technology that had been contributing to a slow decline of the mousaherati in Iraq, the security restrictions have accelerated a drop in their numbers in several cities.

"Mousaheratis have disappeared almost completely," Sabbah says, as he walks through the streets of the city of Samarra, 110 kilometres (70 miles) north of Baghdad.

"There are only some left now, and even they only work sporadically, not every day," adds Sabah, who inherited the position from his father, who did the job for 18 years until his death in 2008.

Authorities normally impose a blanket ban on movement in Samarra between midnight and 4:00 am, with similar curfews in place in other major cities including the capital.

But for Ramadan, which began in mid-July and concludes around August 18, security officials loosen those restrictions, allowing Sabah and others to move around Samarra.

When Ramadan finishes and local residents mark the Eid al-Fitr festival, mousaheratis visit homes in the neighbourhoods they walked and accept small donations for their work.

But because the funds are often paltry, mousaheratis maintain jobs throughout the year -- Sabah, for example, sells cooking oil.

Mousaheratis are common across the Muslim world, but their numbers have dwindled in Iraq.

"In the old days, each alleyway would have its own mousaherati, beating his own drum for suhoor," recalls Abu Jassim, or father of Jassim, a retiree who was sitting in a greengrocer in Baghdad's main commercial Karrada neighbourhood.

"Sometimes, their voices would cross over, because there were so many of them. Children would greet them with screams of happiness when they were on our streets, but now, the fear and insecurity have made them stay away."

In the years following the 2003 invasion, Iraq was engulfed in sectarian violence, peaking from 2006 to 2008, when tens of thousands were killed in rampant bloodshed.

Security has improved since, but attacks are still common and the country has been struck by a relative spike in unrest since the beginning of Ramadan -- the first week of August alone saw 69 people killed.

A legacy of that violence has been city-wide curfews, but also blast walls that have segregated entire neighbourhoods and numerous checkpoints, making movement difficult.

In Baquba, capital of one of Iraq's most violent provinces, Ahmed Abbas had to seek the approval of local security officials, who told the 27-year-old mousaherati "to only move in stable areas."

A combination of the poor security in the city along with the restrictions on movement even for mousaheratis has led to a halving of their numbers compared to last year, when around 60 walked the streets of Baquba before sunrise, according to one provincial council member who declined to be named.

Meanwhile, Mosul, one of Iraq's most violent cities, and the surrounding province of Nineveh no longer sees mousaheratis at all, according to religious officials.

"Mousaheratis have vanished completely in recent years in Mosul because of the security situation, and the absence of support from local officials," complained Mohammed Khaled al-Araibi, an official working with the national Sunni religious foundation's Nineveh offices.

One Mosul resident, construction worker Mukhlis Jarallah, noted that in previous years "large neighbourhoods would wake up to the sounds of an old grandfather."

But, he continued, "the invasion swept away the mousaherati."