Violence in Iraq is on the rise and could lead towards civil war, the head of the UN human rights mission warned on Wednesday.

"Iraq is really at a crossroads. I wouldn't say we're at a civil war yet, but the figures are not looking good," Francesco Motta told AFP.

"Political deadlock in the country, a lack of national vision by a lot of politicians, the outside influences that are coming from the region, Syria and other players, is all having a destabilising effect," he said.

A wave of attacks since the start of the month has left over 190 dead and more than 400 wounded, according to AFP figures based on security and medical sources.

"The deepening sectarian divisions in the country now are manifesting themselves in a way that are even more dangerous than I would say in 2007," when tit-for-tat killings became so bad that "not even the government was counting" the dead, Motta said.

A "surge" of additional US troops combined with Sunni Arab tribes turning against Al-Qaeda helped bring the rampant violence under a semblance of control.

The level of violence reached its lowest level in 2011, with 2,771 people killed, according to UN figures.

But it is once again on the rise, fuelled by widespread Sunni discontent with the Shiite-led government, and fanned by the civil war in neighbouring Syria.

"A lot of the radical groups are getting oxygen from what is going on there," Motta said of Syria.

"The more people die (in Iraq), the greater the chance of counter-reaction and the greater chance it has to spiral out of control," he said.

"If the casualties keep going at this rate it will be well over 5,000 at the end of the year, so we're looking back at figures of 2008," he said.

"We're not at the point where it's irretrievable. We're not at the point where we're at civil war, said Motta.

"But if violence keeps spiralling, if it keeps targeting civilians, if it keeps killing innocent women, men and children, it may come to the point where it will become irreparable, and no one will want to step back from the brink."