Iraqi Prime Minister Nuri al-Maliki has said that Saudi Arabia and Qatar are destabilising Iraq by supporting militant groups and have effectively declared war on the country.

"They are attacking Iraq, through Syria and in a direct way, and they announced war on Iraq," Mr Maliki said in an interview with France 24, in a rare direct attack on the Sunni Gulf powers.

"These two countries are primarily responsible for the sectarian and terrorist and security crisis of Iraq."

Mr Maliki, a Shia Arab, said accusations that he was marginalising Iraq's Sunni minority, were being pushed by "sectarians with ties to foreign agendas with Saudi and Qatari incitement."

He said Riyadh and Doha were providing political, financial and media support to militant groups and accused them of "buying weapons for the benefit of these terrorist organisations."

Mr Maliki also accused Saudi Arabia of supporting global "terrorism," both inside the Arab world and in other countries.

The Iraqi Prime Minister criticised "the dangerous Saudi stance" of supporting "terrorism in the world - it supports it in Syria and Iraq and Lebanon and Egypt and Libya and even in countries outside" the Arab world.

The claims come as attacks across Iraq killed 13 people, including a parliamentary candidate and four children, sources said, as the country suffers its worst violence in years.

Iraq has been hit by a year-long surge in bloodshed that has reached levels not seen since 2008, driven principally by widespread discontent among its Sunni Arab minority and by the civil war in neighbouring Syria.

In Sharqat, north of Baghdad, gunmen shot dead Mohammed Hussein Hamid, who was standing in parliamentary elections scheduled for next month.

Mr Hamid was the second parliamentary candidate to be killed this year, after gunmen murdered Hamza al-Shammari last month.

Election candidates have been targeted in the past, with nearly 20 killed ahead of April 2013 provincial council elections.

In Samarra, also north of Baghdad, a shooting at a checkpoint killed two secondary school students and a policeman, while a roadside bomb blast in a village south of Sharqat killed two children.

Gunmen attacked a checkpoint in Sharqat, killing a police major and a policeman, while a roadside bomb in Khales killed two soldiers.

Iraqi soldiers and police are frequently targeted in bombings and shootings by militants opposed to the government.

In Baghdad, a car bomb exploded near a market in the Qahira area, killing at least two people and wounding four.

One person was killed in a gun attack in the northern city of Mosul, one of the most dangerous parts of the country.

At least 110 people have been killed so far this month, and more than 1,800 since the beginning of the year, according to AFP figures based on security and medical sources.