At least 25 people including a Shia MP have been killed by a suicide car bombing in Baghdad.

The blast on Tuesday struck a checkpoint at an entrance to the Iraqi capital's wealthy Shia area of Kadhimiya.

Police and medics said Ahmed al-Khafaji, a member of the Shia Badr political party and a former deputy interior minister, was among the dead in the blast. Five police officers were also killed, police and medical officials said.

In a second attack, a roadside bomb killed three people on a busy street in the mixed district of al-Qahira in northern Baghdad, police and medical officials said.

It was not clear who was targeted in the al-Qahira blast given that the area's mixed population.

The attack in Kadhimiya marked the third straight day of bombings in mostly Shia areas of the capital. At least 77 people have been killed in the attacks, which have been mostly claimed by the Islamic State of Iraq and the Levant (ISIL).

Source: Agencies