With Prime Minister Narendra Modi on his way to Mumbai to inaugurate Maharashtra government’s controversial mid-sea Shivaji memorial, a police crackdown has forced fishing communities in the city to give up their planned protests against the memorial’s location.

On Friday evening, the Mumbai police detained at least 150 members of the Koli community who took out a motorbike rally with black flags in the Colaba neighbourhood. The detainees included Damodar Tandel, the president of the Akhil Maharashtra Machhimar Kruti Samiti, a leading state-wide fishermen’s association. According to other community leaders, the protesters are unlikely to be released till Prime Minister Narendra Modi has completed the inaugural “bhoomi-pujan” prayer ritual at the site of the planned Shivaji memorial on Saturday afternoon.

Various fishermen’s associations were also served police notices on Friday evening, ordering them not to hold any other form of protest against the memorial during Modi’s visit. Even though the police has not officially announced the imposition of Section 144 of the Indian Penal Code – which prohibits unlawful assembly of more than five people – fishermen claim it has been informally imposed.

“We are still ready to protest, but there is a lot of fear in the community because the police is not allowing groups of more than five people to even step out of our colony alone,” said Mahesh Tandel, the Mumbai president of the Macchimar Sangathan. “I have never seen so much police and coast guard security bandobast in our area.”

The police crackdown will make it nearly impossible for the Kolis to carry out their planned sea rally of 5,000 boats with black flags and a rally of fisherwomen forming a human chain along the coast, without courting arrest or detention.

The fishing community of Mumbai has been opposing the 192-metre high Shivaji memorial ever since it was announced in 2010, because the location of the memorial is a breeding ground for at least 32 species of the city’s most commonly eaten fish. Building the memorial (which will include a statue, museum, amphitheatre and jetties) is likely to involve reclamation of around 60 acres of the sea. This, according to Koli groups, will effectively rob thousands of fishing families of their livelihoods.

This week, said Tandel, fishermen’s associations were finally granted two meetings with Chief Minister Devendra Fadnavis. “He assured us that after December 25, the government will set up a committee to look into our issues,” said Tandel. “Today we may not be able to protest but we are observing a kala din [black day] in our homes.”