Abu Muhammad lies in his front room and tells a story depressingly familiar by Iraqi standards. A public servant, he was travelling to work when he hit traffic at the nearest checkpoint to the highway out of his neighbourhood. So he took a detour and used another checkpoint that would take him through a predominantly Shia area.

One hundred metres from the checkpoint he was blocked by two cars and dragged from his vehicle by masked, armed men. "They didn't seem to know my name. They swore at me and when I asked what they were doing, I was hit on the head with a pistol. I fought and then they shot me in the foot. They tried to put me in the boot but I managed to break free. Then I was running. That's when they shot me again."

It may sound like a story from the bad years of sectarian conflict from 2005 to 2008, when at its peak on average 3,000 people were killed every month. But this episode happened earlier this year, and speaks volumes about the rising tide of sectarian confrontation that has returned to Iraq.

Ultimately, Abu was saved by a crowd of local Shia residents who began shouting at the gunmen. He believes he was targeted for the simple reason he was driving from a Sunni neighbourhood and he has "a Sunni face".

The brother of Amr Ali al-Dulaimi, a Sunni on the security detail of the environment minister, who was gunned down a month ago in the Baghdad suburb of Baya, is also anxious not to be named. "My brother had been looking after a friend's house in a wealthy mixed neighbourhood where he felt safe. It was the end of the school holidays and he thought he'd take his children to get their hair cut and went to a barber he knew in Baya where we grew up, calling him first to make an appointment.

"They'd finished and the kids were in the car when a man dressed in black and wearing a baseball cap stepped up to him and shot him in the head. He'd had no threats I know of. He would have told me. But he was well known in the district from when we lived there. We're not sure who killed him but Shia militias are active in that area."

On Friday, it was the turn of Hussain al-Hadeethi, the imam at the Sunni al-Rasheed mosque in Sab Albor who was shot and wounded leaving his mosque after leading the ishaa – the night prayer.

It is not only Sunnis who are being killed. There are stories of killings on the other side of the sectarian divide – Shia policemen from a unit deployed from Basra who were shot at their checkpoint last week, for example. If the events seem grimly reminiscent of the sectarian war, many observers believe that what is happening in Iraq today is very different.

"It is getting worse right now for all Iraqis," said Pascale Warda, of the Hammurabi Human Rights Organisation. "The security situation now is worse as well as the political situation." She is keen – like many observers – to draw a sharp distinction with what happened in Iraq's sectarian war, not least because political leaders now appear at pains, in public at least, to disavow sectarianism.

"I was at a women's conference last week. The prime minister [Nouri al-Maliki] was there. He made an excellent speech saying Iraq would not go back to the sectarian days. I also saw him speak at a church and say the same. All of which is very good but I was bothered by the fact that he did not acknowledge the speaker of the parliament [Osama al-Nejafi, a Sunni very publicly at loggerheads with Maliki] nor did Nejafi acknowledge Maliki."

Warda, like others spoken to by the Guardian, blames a complex coincidence of events for the present violence.

Sunnis in the province of Anbar, centred on the city of Falluja, have stepped up protests, complaining of the marginalisation of Sunnis within Iraqi institutions. The government in Baghdad has clamped down to prevent the protests spreading to the capital.

The political backdrop has not helped. A stalemate has persisted since the last national elections in 2010, when Maliki failed to win a majority but managed to pull enough Shia factions around him to govern. Since then, Sunni Iraqis have accused Maliki of being a dictator. He has accused his detractors of plotting against the state.

The result, Warda argues, is not sectarian hatred for its own sake as was visible five years ago. Instead, where it exists, it is defined by a political agenda.

If the dangers are apparent in the sporadic killings and bombings that blight Iraqi life, it is also being exacerbated by marginal actors with the power to frighten and by jostling for the spoils of rampant corruption. Last month the head of Iraq's Hizbollah Battalions Wathiq al-Battat announced the creation of the Mukhtar army, a new Shia sectarian militia – allied with Iran's Revolutionary Guards – whose aim he said was to "combat terrorism", which distributed leaflets in the Sunni Jihad neighbourhood last month warning Sunnis: "You are the enemy. Leave along with your families."

"Wathiq al-Battat's a joke," explains Saad al-Muttalibi, a senior Dawa party official close to the prime minister. "He doesn't even know how to load a gun!" He concedes insecurity is a problem, but prefers to blame it on more complex factors.

"There are problems in different places associated with different things. Sometimes it is hard to unravel exactly what is going on.

"In Anbar province you can feel the growing influence of al-Qaida," said Saad al-Muttalibi. "We agreed with the local authorities to pull back from Falluja and let them police it, but as soon as we did al-Qaida were back within five minutes. And you have to ask who benefits from the instability – al-Qaida and the Ba'athists [supporters of the party of Saddam Hussein]."

Notably absent from the stage is the Mahdi army, the Shia militia loyal to the cleric Moqtadr al-Sadr which perpetrated some of the worst abuses during the sectarian war. But if the Mahdi army has been conspicuous by its absence, a new factor has been introduced – the dangerously destabilising influence of the war in Syria next door, which also risks feeding into sectarian divisions in a conflict where the Free Syrian Army is largely Sunni and Bashar al-Assad's regime is dominated by Alawites, a branch of Shia Islam.

At the beginning of the month, 42 Syrian soldiers loyal to Assad who had fled into Iraq were ambushed and killed along with 11 Iraqi policemen, by suspected Sunni militants.

Ibrahim al-Sumydai, a Sunni and former senior adviser to the interior ministry, with connections to top officials in the Iraqi government is worried by developments on both sides. He believes the failure of the government to listen to the complaints of the Anbar protesters is in danger of strengthening a resurgent al-Qaida in Iraq. He fears too that with provincial elections in April neither the Sunni speaker of the parliament nor the PM is prepared to appear weak to their own sectarian constituencies, leading to a stalemate.

"My own nephew was arrested and confessed under duress to crimes he had not committed. I have connections but in the end I had to pay to get the false charges dropped. Every Sunni family has had a similar experience," he said.

"But I know for a fact that the prime minister wants to act and defuse the situation. The way the pressure on him is being presented by his opponents he is in a difficult position because they are giving the impression their aim is to twist his arm. If he is seen to back down to the demands he will lose support in the local elections among his own people. The same is true of Nejafi and his supporters. They don't appeal across the country only to their own streets.

"When this crisis started I tried to appeal to the prime minister as a mediator but nothing is happening, he partially responded but it was not enough.

'My concern?" he adds, answering himself. "Both sides are playing with fire. And the question is do we have time to solve this crisis?"