Almost 800 people have been killed in violence across Iraq in May, the United Nations has said, making it the deadliest month for the country this year.

Of the 799 people killed, 196 were members of the Iraqi security forces while and the rest were civilians, the UN mission to Iraq (UNAMI) said on Sunday.

It said that 1,409 Iraqis, including 1,108 civilians, were wounded.

Attacks by Sunni fighters have been gaining momentum in Iraq during the past year, underlining the challenges facing the government.

The real toll is higher because the UN figures do not include casualties in the western province of Anbar, where the Iraqi army has been fighting tribal and fighter groups since they overran two cities at the start of the year.

Excluding Anbar, UNAMI's figures show that the worst-hit city was the capital Baghdad, with 315 people killed. The northern province of Ninevah came in second with 113, followed by Salahuddin province with 94 deaths.

The UN said figures from the Anbar health directorate put the number of civilian casualties there at 195.

Maliki in power

Despite deteriorating security, Iraq's prime minister, Nouri al-Maliki, won the largest share of parliamentary seats in national elections last month, a blow to his opponents who blame him for leading the country to ruin.

Bloodshed remains below the levels seen in 2006 and 2007, when sectarian violence reached their peak, but last year was Iraq's deadliest since violence began to ease in 2008.

"I strongly deplore the sustained level of violence and terrorist acts that continues rocking the country," UN envoy to Iraq Nikolay Mladenov said in a statement.

The previous month's death toll stood at 750, according to UNAMI, making April the second deadliest month of the year.