Hyogo Prefectural Police on Monday raided the Akashi Police Station and Akashi Municipal Office in their probe of alleged professional negligence resulting in death and injury in connection with last month's fatal crush after a fireworks event in Akashi, Hyogo Prefecture.

Investigators search the Akashi Police Station in connection with the fatal crush of 11 people after a fireworks event in the city in July.

Eleven people, including nine children, were killed and over 200 were injured in the incident, which occurred on a crowded pedestrian overpass.

The city, which organized the July 21 fireworks display, allegedly drew up a faulty crowd-control plan, while Akashi police, who were in charge of managing the flow of people that evening, are suspected of mishandling the operation, according to the prefectural force.

It is rare for municipal authorities and police to be investigated for a fatal accident blamed on extreme crowding. The Kobe District Public Prosecutor's Office cooperated in Monday's raids in an effort to ensure fairness, since the case involves police.