Bombings in Iraq, including one near a governor's convoy, killed eight people on Tuesday a day after a wave of attacks left 50 dead ahead of the first elections since US troops withdrew. A car bomb killed four people and wounded 15 in Aziziyah, while a roadside bomb killed a soldier and wounded two near Mussayib, both south of the capital, security and medical officials said. Three separate blasts north of Baghdad killed three people and wounded eight others, and a roadside bomb exploded near a convoy carrying Nineveh province's Governor Atheel al-Nujaifi near the main northern city of Mosul, though no one was hurt. Gunmen also attacked a military site northwest of the disputed city of Kirkuk in the north, wounding two soldiers, while two workers on an irrigation project were kidnapped west of the city. The spate of bombings comes a day after more than 30 attacks killed 50 people and wounded almost 300, raising further questions about the credibility of April 20 provincial elections seen as a key test of Iraq's stability and its security forces. A total of 14 election hopefuls have already been murdered and just 12 of the country's 18 provinces will be taking part in the vote. Soldiers and policemen cast their ballots for the provincial elections on Saturday, a week ahead of the main vote, the country's first since March 2010 parliamentary polls. It is also the first election since US troops withdrew from Iraq in December 2011. The election comes amid a long-running crisis between Prime Minister Nuri al-Maliki and several of his erstwhile government partners, which officials and diplomats say insurgent groups exploit by using the political differences to enhance their room for manoeuvre on the ground. More than 8,000 candidates are contesting 378 seats on provincial councils, with an estimated 16.2 million Iraqis eligible to vote.