By Sylvia Westall and Suadad al-Salhy
BAGHDAD (Reuters) - Gun attacks and a bombing killed at least seven more people in Iraq on Sunday, police said, after a day of carnage aimed mainly at Shi'ite Muslims celebrating the end of Ramadan.
The United States condemned a wave of car bombings which police and medical sources said killed nearly 80 people across Iraq on Saturday, saying those who had attacked civilians during Eid al-Fitr festivities were "enemies of Islam".
Bombs tore through markets, shopping streets and parks late on Saturday as Iraqi families were out celebrating the end of the Muslim fasting month.
Iraq's Interior Ministry said media reports about the attacks had been exaggerated in a way that would give a morale boost to attackers. It said 21 people had been killed across Iraq in the multiple attacks and that a recent security crackdown called "Avenge the Martyrs" had been effective.
Eighteen months since the last U.S. troops withdrew, Sunni Islamist militants have been gathering force in their insurgency against Iraq's Shi'ite-led government.
The civil war in neighboring Syria has aggravated tensions and the Interior Ministry said last month it was facing an "open war".
The renewed violence has raised fears that Iraq could relapse into the sectarian bloodbath of 2006-2007 when tens of thousands were killed.
The State Department said Saturday's attacks bore the hallmarks of al Qaeda's Iraqi (AQI) branch. It reiterated that it was offering a $10 million reward for information leading to the killing or capture of Abu Bakr al-Baghdadi, the AQI leader.
"The United States condemns in the strongest possible terms the cowardly attacks today in Baghdad," the State Department said. "The terrorists who committed these acts are enemies of Islam and a shared enemy of the United States, Iraq, and the international community."
It said the United States would work closely with the Iraqi government to confront al Qaeda and discuss this during a visit of Foreign Minister Hoshiyar Zebari next week to Washington.
This has been one of the deadliest Ramadan months in years, with bomb attacks killing hundreds. Explosions in Baghdad on Tuesday killed 50.
On Sunday, gunmen opened fire at a checkpoint manned by "Sawha", a government-backed Sunni militia, killing two and wounding two in the town of Buhriz, about 60 km (35 miles) northeast of Baghdad, police said.
Further north, gunmen attacked a busy park in the town of Balad, killing two and wounding three, police said.
To the south of the capital, three anti-terrorism squad officers were killed and nine wounded by a roadside bomb in the town of Mahaweel, 60 km (35 miles) from Baghdad.
More than 1,000 Iraqis were killed in July, the highest monthly death toll since 2008, according to the United Nations.
"This carnage reflects the inhuman character of its perpetrators," United Nations envoy to Iraq Gyorgy Busztin said. "All honest Iraqis should unite to put an end to this murderous violence that aims to push the country into sectarian strife."
Since last year, Iraq's al Qaeda branch has merged with one of the most powerful Sunni Islamist rebel groups in Syria to form The Islamic State in Iraq and the Levant. The group now controls towns and villages on both sides of the desert frontier, with access to funds, weapons and recruits.
Al Qaeda claimed responsibility last month for simultaneous raids on two Iraqi prisons and said more than 500 inmates had escaped in the brazen operation.
The reward for Baghdadi is second only to that offered for information leading to the capture of Ayman al-Zawahri, the overall chief of al Qaeda's network, the State Department said.
(Additional reporting by Ali al-Rubaie in Hilla, Ghazwan Hassan in Tikrit, Suadad al-Salhy in Baghdad and a Reuters reporter in Baquba; Editing by Andrew Roche and Tom Pfeiffer)