Bombings and clashes killed 23 people in Iraq on Tuesday, security and medical officials said, after Al-Qaeda's Iraq front group announced a new offensive in the Muslim holy month of Ramadan.

The latest violence brings the number of people killed in attacks across the country in July to at least 280, according to an AFP tally based on security and medical sources.

An interior ministry official said two car bombings in Baghdad's central Karrada area, one of them a suicide attack, killed 12 people, among them seven police, and wounded 47, among them 10 police.

A medical official put the toll at 19 killed, including five police, and 50 wounded, among them 10 police.

The interior ministry official also reported another suicide bombing as well as armed clashes.

A health ministry official at the scene of that attack, which was also in central Baghdad, said he saw the bodies of seven interior ministry special forces personnel and two civilians.

The interior ministry meanwhile said in a statement on its website referring to one of the Baghdad attacks that its "forces thwarted a terrorist attack targeting the anti-terrorism directorate," which was aimed at freeing detainees.

Three attackers entered the directorate after setting off a bomb followed by a car bomb at the gate, but guards killed two of them and no detainees were freed, it said, adding that a lieutenant colonel was killed and two guards wounded.

Official tolls in Iraq are often much lower than those given by other sources.

One of the earlier blasts caused extensive damage to a building and destroyed multiple cars, shattered shop windows and scattered debris across the street.

Emergency vehicles and security forces quickly descended on the scene of the blast.

Separately, two people were killed and three wounded by a car bomb north of Fallujah, a police major in the western province of Anabar and Doctor Assem al-Hamdani of Fallujah Hospital said.

Al-Qaeda front group, the Islamic State of Iraq, said in a July 25 statement that attacks that killed 113 people two days before were "part of the new military campaign aimed at recovering territory," that its leader Abu Bakr al-Baghdadi announced earlier this month.

Al-Qaeda is regarded by Iraqi officials as significantly weaker than at the peak of its strength in 2006 and 2007, but it is still capable of spectacular mass-casualty attacks across the country.

The Tuesday attacks came a day after gunmen shot dead a television presenter and wounded his mother, wife and four-month-old baby boy, according to the Journalistic Freedoms Observatory media rights group and a police officer.

Iraq regularly ranks near the bottom of global press freedom rankings. It was at 152nd place out of 179 countries in media rights watchdog Reporters Without Borders' 2011-2012 World Press Freedom Index, down 22 from the year before.

Iraq saw a spike in unrest in June, when at least 282 people were killed, according to an AFP tally.