BAGHDAD, Jan. 15 (Xinhua) -- Iraqi Prime Minister Haider al-Abadi Monday issued orders for the security forces to track the extremist terrorists and bring them to justice, hours after massive twin bomb explosions in downtown Baghdad.

A statement by his office said that Abadi, who is also Commander-in-chief of Iraqi forces, held a meeting with commanders of the security forces and the intelligence service of Baghdad and gave his directions "to chase the sleeper cells of terrorists and bring them to justice in order to ensure the security of the citizens."

Abadi's comments came hours after twin bomb explosions, one of them by a suicide bomber, ripped through a crowded site near al-Tayaran Square where many construction workers usually gather waiting for potential employers, leaving at least 16 people killed and some 67 others wounded, according official reports from the Iraqi Interior Ministry.

The car bombing is the second this year in Baghdad city, which has been witnessing tangible improvement in security as the Iraqi security forces managed during the past few months to regain control of strongholds of the extremist IS militant group across the country.

Two days ago, a suicide bomber who detonated his explosive-laden motorcycle at the crowded Adan Square at the entrance of the holy Shiite neighborhood of Kadhmiyah, leaving two people killed and 24 injured, along with destroying 11 cars.