They also held a token hunger strike outside the local press club in the city.
The protesters led by Sindhu Nawaz Ghangro told journalists as quoted by Dawn News that being lower riparians, people of Sindh were owners of the Indus, hence they would resist construction of any new dam on the river because it would spell disaster for the province.
They demanded the government to give up their plan to construct the dam on Indus.
They said protests will be expanded and highways might be blocked if their demand is not met.
The Pakistani government recently signed a Rs 442 billion contract with a joint venture of China Power and Frontier Works Organisation (FWO) for the construction of the Diamer-Bhasha dam.