Hizb-ut-Tahrir is a banned Islamist group that seeks to establish an Islamic caliphate. A caliphate is an Islamic state led by a supreme religious and political leader known as a caliph, considered a successor to the Prophet Muhammad. - Police in Dhaka, Bangladesh, used batons, stun grenades, and tear gas to disperse thousands of members of Hizb-ut-Tahrir. - The protesters were marching near the Baitul Mokarram Mosque, a major mosque in Dhaka. - Hizb-ut-Tahrir is a banned militant group advocating for the replacement of Bangladesh's secular democracy with an Islamic caliphate. - Several protesters were arrested, and many people were injured during the clashes with police.