A suicide bomber killed a Sunni Iraqi MP and six others Tuesday, wrapping his arms around the lawmaker before blowing himself up, officials said, amid a political crisis engulfing the country.

The killing of Ayfan Saadun al-Essawi comes just two days after Finance Minister Rafa al-Essawi, a fellow Sunni and a member of the same tribe and political bloc, escaped an apparent assassination attempt as his convoy was passing near where Tuesday's attack took place.

It is likely to further enflame tensions with Iraq already grappling with a political crisis that has pitted Prime Minister Nuri al-Maliki against Essawi's secular Sunni-backed Iraqiya bloc.

Lawmaker Essawi, 37, had been inspecting a road under construction south of Fallujah at the time of the attack.

"The moment he stepped out of the car to check out this road between Fallujah and Amriyah, at this moment, there was a man," said Sohaib Haqi, the lawmaker's office chief. "He came to him, hugged him, said Allahu Akbar, and blew himself up."

Doctor Assem al-Hamdani at Fallujah hospital put the overall toll at seven dead -- Essawi, four of his bodyguards and two civilians -- and six wounded, including four of the lawmaker's guards.

Essawi was also a former leader of the Sahwa, a collection of Sunni tribal militias that turned against Al-Qaeda and sided with the US military from late 2006, helping turn the tide of Iraq's bloody insurgency.

He was himself inducted into parliament after another Sunni MP, Khaled al-Fahdawi, was killed in a suicide attack at the Umm al-Qura mosque in west Baghdad in August 2011.

Tuesday's blast comes amid a political crisis in Iraq.

Weeks of anti-government demonstrations in Sunni Arab majority areas, supported by Iraqiya and other groups, have hardened opposition against Maliki, a Shiite.

The premier is at loggerheads with Iraqiya, which remains a part of his national unity government, over its accusations of Maliki acting in an authoritarian and sectarian fashion in the run-up to key provincial polls.

Kurdish parties and powerful Shiite cleric Moqtada al-Sadr, whose movement counts 40 members of parliament and five ministers among its ranks, have also publicly opposed Maliki.

The demonstrations in Sunni areas have decried alleged misuse of anti-terror laws to hold members of the minority community, and claim Sunnis are being targeted by the Shiite-led authorities.

In a bid to placate the rallies, a top Iraqi minister publicly apologised on Monday and said Baghdad had released 335 prisoners in the past week.

The crisis comes with barely three months to go before provincial elections, a key barometer of support for Maliki and his opponents ahead of a general election next year.