The Islamic State group Sunday claimed responsibility for a car bomb attack outside a popular Baghdad restaurant that killed 15 people, including four policemen and a media figure.

Saturday's attack, one of the deadliest in the Iraqi capital this year, took place in Karrada, a district packed with shops and restaurants. It was the latest in a series of similar bombings in Baghdad.

It killed 15 people and wounded 51, a police colonel told AFP on Sunday, revising an earlier toll of 14 dead and 39 injured.

IS radio Al-Bayan said the jihadist group carried out the attack and targeted a Shiite militia helping Iraq's government forces fight the extremist militants.

"The soldiers of the caliphate managed to blow up an explosive laden car... in the area of Karrada," the broadcaster said.

Among those killed was Ammar al-Shahbander, chief of mission in Iraq for the Institute for War and Peace Reporting (IWPR), the interior ministry and two of his friends said.

Shahbander, who was born in 1976 according to his friends, was leaving a cafe in Karrada when the explosion happened, his friends said.

A statement by the interior ministry described him as a "martyr of the Iraqi press".

British-educated Shahbander was responsible for IWPR activities in Iraq and neighbouring Syria, and was in charge of a programme to set up a new media institute in Iraq.

A veteran Middle East journalist, Shahbander was mourned by Brett McGurk, US President Barack Obama's deputy envoy for the coalition fighting IS in Syria and Iraq.

"Tonight in #Baghdad, terrorists took the life of my friend... They will never silence his spirit, or that of the Iraqi people," McGurk tweeted late Saturday.

Saturday's bombing in Baghdad was the second claimed by IS in as many days.

On Thursday, 11 people were killed and more than 40 wounded in a wave of attacks in Shiite districts of the Iraqi capital which the jihadists also said they carried out.