 Sumatran traders had arrived at the river's estuary in the 1780s and established settlements like Kampung Rawa and Kampung Makam.Ethnic Tamils also settled along the river; whilst some professed their Muslim faith, others retained their Hindu beliefs and built a handful of Hindu temples along the river bank.The existence of Muslim and Hindu places of worship located adjacent to one another had in the past provoked racial and religious tensions.