Iraqi voters braved mortar attacks and death threats to cast their ballots on Sunday in the country's crucial national elections. Some 5,300 polling centers opened their doors to voters at 7 AM (0400 GMT), and an election official earlier said at least 72 percent of those eligible had turned out by 2 AM (1100 GMT).

Polling stations closed at 5 PM (1400 GMT), but voters waiting in line were still allowed to cast ballots, according to the election authorities.

The percentage of registered voters who had gone to the polls in some Baghdad neighborhoods reached 95 percent, said Adel al-Lami, a member of the Independent Electoral Commission. But he offered no overall figures for those who voted.

Around 13 million, about half the population, had registered to vote. Some of those eligible to did not register due to intimidation or because they were boycotting the polls.

The figure announced by al-Lami was higher than most expected.

Earlier in the day, Carlos Valenzuela, the UN’s chief electoral official in Iraq, offered a much more cautious assessment, saying turnout appeared to be high in many areas, but it was too early to know for sure.

Several hours after the beginning of the voting, some political parties trying to keep track said turnout in the election might reach 50 percent.

"The reports we are receiving indicate that the turnout will hit more than 50 percent. Iraqis are looking at these elections as an issue of dignity," said Planning Minister Mehdi al-Hafedh Hafedh, whose secular Independent Democrats had sent supervisors to monitor the voting process.

Oil Minister Thamir al-Ghadhban, a leading candidate in interim Prime Minister Iyad Allawi's electoral list, also said his party's monitors were reporting a big turnout.

"We are seeing huge numbers across Iraq who want to defeat terror with their vote," he said, "I will not be surprised if turnout exceeds half."

In the Kurdish-dominated north and the mostly Shiite south, the turnout is overwhelming. However, few Iraqis are voting in Sunni areas due to lack of security and calls for a boycott from some Sunni parties hostile to the military presence of the US and UK.

Meanwhile, a group led by Abu Musab al-Zarqawi, the most wanted man in Iraq, claimed responsibility for suicide attacks on several polling stations in Iraq.

"Lions from the martyrs' brigade of the al-Qaida Organization for Holy War in Iraq attacked several polling stations in Baghdad and elsewhere," said a statement posted on an Islamist website.