BAGHDAD (AFP) - Car bombs exploded in crowded commercial areas of the Iraqi capital Friday, killing at least 18 people, the latest in a string of deadly blasts in the city, officials said.

One car bomb hit Baladiyat in eastern Baghdad, killing at least 13 people, while another struck Adhamiyah in the capital's north, killing at least five, security and medical officials said.

The bombings also wounded more than 40 people.

Militants led by the powerful Islamic State extremist group have seized large areas of Iraq since June, and Iraqi security forces are still struggling to regain ground.

The militants have been kept from reaching Baghdad in force and would face major challenges if they tried to occupy part of the city, but they are able to carry out deadly bombings with impunity.

Bombings in and around Baghdad killed at least 26 people on Thursday, while a suicide car bomb on Tuesday killed 28 people, among them an MP who was also a senior Shi'ite militia commander.