BAGHDAD — Iraq's presidential council on Tuesday again postponed nationwide parliamentary elections, setting March 7 as the date for the vote in what has become a seven-week delay likely to feed concerns about an increase in violence.

The postponement came hours after the council decided to hold the vote on March 6, a move that followed on the heels of a series of coordinated attacks killed at least 127 people and wounded more than 500 in the worst day of violence in the Iraqi capital since October.

Three car bombs struck near government sites in the Iraqi capital, the third time since August that government buildings were targeted by multiple blasts that brought massive casualties. U.S. and Iraqi military officials had warned of the chance of increased pre-election violence aimed at destabilizing the government.

It was not clear why the three-member presidential council agreed on one date and then hours later moved it back by one day. But Qassim al-Aboudi, a senior electoral commission official, said the decision gave election workers more time to organize the nationwide vote.

The election date is a week later than what election officials initially recommended, said Faraj al-Haidari, the head of Iraq's Independent High Electoral Commission.

"We needed more time to organize voting abroad and time to complete preparations for the elections in general," al-Haidari said.

The commission requested the Jan. 16 elections be postponed after the elections law was vetoed by Vice President Tariq al-Hashemi, who wanted a greater political voice for minority Sunni Arabs and changes in the distribution of seats in Iraq's expanded 325-seat parliament.

On Monday, the electoral commission recommended a 45-day delay in the elections that would have pushed it to the end of February. But al-Haidari said the council decided to delay the elections a bit longer because of a series of religious holidays that could interfere with the planning.

The U.S. military plans to withdraw all but 50,000 of its roughly 120,000 troops from Iraq by Aug. 31, 2010. But the delay could complicate the timetable for that withdrawal, which American commanders have said will begin 60 days after the election.

America's top commander in Iraq, Gen. Raymond Odierno, has said the parliamentary elections will be the first nationwide vote run solely by Iraqis, and that any related violence will probably happen within the first 60 days after the vote.

Ali al-Adeeb, a Shiite lawmaker and a member of Prime Minister Nouri al-Maliki's inner circle, said the bombings were an attempt by insurgents to send the message that the political process in Iraq was failing.

"These bloody bombings aim to undermine the political process, especially the elections process," he said.

Associated Press Writer Sameer N. Yacoub contributed to this report.