Iraqi Prime Minister Mustafa al-Kazemi has already ordered an investigation into the incident. 

مراسل العربية: ٢٠ قتيلا و ٤٥ جريحا بتفجير مدينة الصدر شرق بغداد


# العربية pic.twitter.com/g2IdZTIJwJ

- العربية (@AlArabiya) July 19, 2021

As specified, none of the parties has yet taken responsibility for the attack, however, IS has previously claimed responsibility for similar attacks *.

* "Islamic State" (IS, ISIS) - the organization was recognized as terrorist by the decision of the Supreme Court of the Russian Federation of December 29, 2014.