A suicide bombing in northern Iraq on Wednesday killed the leader of a provincial political party and four relatives, officials said, on the eve of elections his bloc was to participate in. Yunus al-Ramah, head of the United Iraq party, had been hosting a social gathering at his home in the town of Al-Hadhr, in Nineveh province, when the attack took place, according to security and medical officials. \"The suicide bomber targeted people gathering in Ramah\'s garden,\" said police First Lieutenant Islam al-Juburi. Five people were killed -- Ramah and four of his relatives -- and six others wounded, Juburi and a doctor said. Ramah\'s United Iraq party is seen as allied to Prime Minister Nuri al-Maliki. He was not running in the June 20 polls, but several of his party members were candidates. The attack comes ahead of Thursday\'s elections in Nineveh and Anbar, two Sunni-majority provinces where polls were delayed by officials who cited security concerns. Twelve other provinces held elections on April 20. No group immediately claimed responsibility for the attack, but Sunni militants linked to Al-Qaeda have sought to intimidate candidates, particularly in a bid to derail elections in majority-Sunni areas of Iraq. Nineveh province is one of Iraq\'s most violent, on a per capita basis, according to British NGO Iraq Body Count. There has been a heightened level of unrest since the beginning of the year in Iraq, coinciding with rising discontent among the Sunni Arab minority that erupted into protests in late December. Analysts say a lack of effort by the Shiite-led authorities to address the underlying causes of the demonstrations has given militant groups fuel and room to manoeuvre to carry out their activities. Political leaders have pledged to resolve outstanding disputes, and Prime Minister Maliki has met with two of his main rivals in a bid to ease tensions, but no tangible moves have been agreed.