(CNN) -- Attackers in Iraq killed 18 people on Wednesday, authorities said.
At least five people were killed and 24 others were wounded when a car bomb exploded in the main commercial street of Karrada district in central Baghdad, police said. Baghdad is the nation's capital.
In the nation's north, at least 13 Iraqi soldiers were killed and 11 others were wounded when 20 gunmen carried out a coordinated attack on a military base, health and police officials in Mosul said. The attack, which happened during a shift change, took place at a base in al-Mahelabia, about 60 kilometers, or 37 miles, south of the sprawling city of Mosul.
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.