MOSUL, Iraq (Reuters) - Aid convoys linked to paramilitary groups have begun making regular deliveries to Mosul districts recaptured from Islamic State, bringing much-needed relief but also fears that their Shi’ite backers are encroaching into the mostly Sunni city.

FILE PHOTO: Civilians queue for humanitarian aid packages in Al Ghizlane district as the battle against Islamic State's fighters continues in Mosul, Iraq, March 20, 2017. REUTERS/Youssef Boudlal/File Photo

The columns of trucks and cars carrying food, water and blankets from Shi’ite cities in southern Iraq are welcomed by hungry and war-weary residents of Mosul, Islamic State’s last major Iraqi stronghold.

But their affiliation with the Hashid Shaabi, or Popular Mobilization Forces (PMF) - a state-run umbrella including Shi’ite militias - is clear, as they fly the flags of those groups and are often accompanied by heavily armed men.

Local leaders and many among the Mosul population say it could be the first sign of Shi’ite parties trying to extend their influence as the battle against the jihadists winds up.

Perversely, they say, the humanitarian help raises the specter of sectarian strife in a country torn apart by it.

The PMF says the convoys are charitable and nothing more, and that the weapons are to protect those bringing supplies on long drives from the south.

The tension the armed presence can create, however, is already visible.

During a terse exchange on Sunday with Iraqi police, gunmen on a convoy from the Shi’ite holy city of Kerbala jumped off their vehicles at a checkpoint south of Mosul carrying assault rifles, some with fingers on triggers.

A policeman mounted the gun turret of an armored car in case the argument escalated.

“No problem, insha’allah (God willing),” said one of the convoy organizers, who gave his name only as Ali.

The vehicles were eventually waved through into Mosul, flying the banner of a Kerbala-based Shi’ite militia.

A local tribal leader and former councilman for Nineveh province, of which Mosul is the capital, said this kind of action laid bare Shi’ite attempts to expand influence in mainly Sunni northwestern Iraq.

“Shi’ite brothers have exploited the war conditions to pave the way for their project, it’s a gradual infiltration,” Sheikh Ali, told Reuters by phone. He asked not to be identified by his last name for fear of reprisals.

“It’s “Shi’isation” of Mosul city - an attempt at hegemony.”

Abdul Rahman al-Wagga, a current council member, said with Islamic State ousted there was concern over encroachment by political factions with armed branches that have not previously had a strong presence in the area.

“This aid ... is being brought in by factions or parties which have armed wings.

“When a political side comes to a city or region, and has an armed wing, the fear is that this armed wing will be used for political interests,” he said.

Senior PMF figure Kareem al-Nuri denied there were political goals behind the aid.

“These fears have no place,” he said.

“Humanitarian work ... does not mean demographic change,” he added, saying the convoys were the “duty” of the PMF, and were to show solidarity and build trust.

‘SECTARIANISM DOESN’T DISAPPEAR’

Reaction from locals, who have lived under the brutality of Islamic State, has been mixed.

In western Mosul, the convoy that had driven through the checkpoint distributed blankets, water and food.

“They’re giving good amounts of aid, and it includes fresh food and meat - better than we would get from other organizations,” Omar Ibrahim, a 39-year-old carpenter and former soldier, said. “Sectarianism died with Daesh (Islamic State).”

But another resident suspected ulterior motives.

“We’re not against the aid, but against people imposing their views,” Mahmoud, 39, said quietly as Shi’ite gunmen and federal police controlled the crowd.

“The way they’re doing this - flying flags and coming in with guns, tells you there’s something else behind it. It’s a friendly face, but the aim behind it is domination,” he said. He did not give his full name for fear of reprisals for speaking out on a sensitive topic.

It was in Mosul that Islamic State leader Abu Bakr al-Baghdadi declared the Sunni extremists’ caliphate spanning areas of Iraq and Syria in 2014. The U.S.-backed Mosul offensive is on track to end the group’s sway over territory in Iraq nearly three years later.

Prime Minister Haider al-Abadi recognizes the need to avoid recreating conditions that allowed IS to take root, including corruption in the security forces and marginalization of Iraq’s minority Sunni population under predecessor Nuri al-Maliki.

To avoid sectarian tension, Abadi said the army and police would be the only forces to enter Mosul in the battle against IS, not the PMF.

PMF involvement in the campaign has however been crucial, helping encircle the jihadists in areas around Mosul. But reliance on the Shi’ite groups will likely increase as the battle strains Iraq’s military, analysts say.

Ramzy Mardini, a fellow at the Atlantic Council, said that behind the aid effort is likely a PMF bid to have a permanent presence either in or around Mosul.

“It’s a war zone and the ultimate aim is to capture enemy territory. In that context, they’re armed participants regardless of whatever role they play in the overall effort,” he said.

“The government’s degree of reliance on militia forces, Shi’ite or Sunni, only increases going forward,” he said.

At another aid distribution point, one local said he feared PMF military encroachment into Mosul city.

“The reason for what’s happening in Mosul in the first place is sectarianism. That doesn’t just disappear.”