(CNN) -- As Iraqi police and troops cast ballots early in the country's first parliamentary elections since the 2011 withdrawal of U.S. forces, 32 people were killed in attacks across the country on Monday.
The shootings and explosions targeting elections centers wounded 92 people, police and health officials in Baghdad and several provinces told CNN.
In several instances, suicide bombers detonated explosives at polling centers as security forces waited in line to vote.
Iraq has been beset with political and sectarian violence for months, often pitting Sunnis -- a minority in Iraq -- against Shiite Muslims, who came to dominate the government after Iraqi leader Saddam Hussein was overthrown in 2003.
Violence has escalated over the past year. The United Nations said 2013 was the deadliest year in Iraq since 2008, with more than 8,800 people killed, most of them civilians.
Police and military have two days to cast votes before the rest of the country's registered voters cast their ballots in parliamentary elections Wednesday.
Some 277 political entities across Iraq will compete for 328 seats of the Iraqi Council of Representatives, the country's parliament. There are 9,032 candidates.
"These elections mark an important milestone in Iraq's democratic transition and can contribute to greater peace and stability in the country," U.N. Secretary-General Ban Ki-moon's office said in a statement.
Ban condemned the wave of violence and terrorist attacks and urged leaders to try to ensure all Iraqi men and women can take part in the elections.