Three Iraqis have been killed in a rocket attack in the capital, Baghdad, Iraqi police say.
Overall damage to infrastructure in the war is put at $55bn
The unidentified victims were travelling in a car near a telephone exchange office when they were hit.
A bomb exploded near another telephone exchange in Baghdad on Wednesday, sparking fears that insurgents might be targeting the country's infrastructure.
The violence follows Iraq's worst day since the end of the war when at least 181 people were killed.
The new figures released by US and Iraqi officials on Thursday come after much confusion surrounding the attacks in Baghdad and the holy city of Karbala on Tuesday.
The US has announced a multi-million dollar programme to strengthen security on Iraq's borders to prevent infiltration by foreign militants.
The US says the attacks will not affect the planned handover of sovereignty to local Iraqis by the end of June.
On Friday, Iraqi leaders are due to sign the country's new interim constitution - one of the first steps towards the handover.
Witnesses said Thursday's rocket had skidded along the ground after the initial impact, hitting a car and killing its occupants.
"Three were killed and two were wounded," policeman Luay Majeed told Reuters news agency.
Tuesday saw the worst day of violence since the end of the war
A large crowd of Iraqis gathered at the site of the attack watching the burned-out wreckage of the car and chanting anti-US slogans.
On Wednesday, guerrillas rocketed a telephone exchange across the city in the Mansour neighbourhood, killing one person and knocking out international telephone services for a large swathe of the country.
Iraqi infrastructure has often come under attack by insurgents opposed to the US-led occupation. Several oil installations have been blown up since the end of the war.
On Thursday, the coalition released revised - and possibly final - casualty figures for Tuesday's bomb attacks which came at the climax of the Shia Muslim festival of Ashura.
In Baghdad 71 people were killed and 320 wounded. In Karbala 110 Shias were killed and 233 injured.
The head of the Iraqi Governing Council, Mohammed Bahr al-Uloum, confirmed the figures - he had put the deaths at 271 a day earlier.
Mr Uloum visited a hospital where survivors of the attack at Baghdad's Kadhimiya shrine were being treated and blamed the US.
"The coalition forces are part of the authorities and they are in charge of maintaining security, so they should do all that they can to maintain security," he told reporters.