Four mortars exploded on Saturday near a polling station in central Iraq's Tikrit, home of executed Sunni dictator Saddam Hussein, police said. The bombs exploded near several poll stations in Tikrit as local residents headed to vote in the provincial elections, a local police officer told foreign news agency. There were no immediate reports of casualties. About 15 million eligible Iraqis have been called to cast ballots in 14 of 18 provinces at thousands of voting centres that opened at 7 am (0400 GMT) and will close at 5 pm (1400 GMT).