The streets in major cities across Tanzania were deserted early on Tuesday as the government urged citizens to stay home for Independence Day celebrations.

Police and soldiers were deployed in force across the country to prevent planned protests against the violent suppression of demonstrations around the October elections.

In the worst political violence since independence, hundreds of people were killed and more than 2,000 others detained in three days of protests over the ruling party’s victory in the disputed poll.

It also saw President Samia Suluhu Hassan re-elected with nearly 98 per cent of the vote after leading opposition candidates were barred from taking part.

In the run-up to Tuesday’s anniversary of mainland Tanzania’s independence from Britain in 1961, the government said demonstrations would amount to a coup attempt.

It pre-emptively declared them illegal.

Police trucks and officers on foot patrolled Tuesday morning in the commercial capital, Dar es Salaam, the administrative capital, Dodoma and the north-eastern city of Arusha.

Roadblocks were erected near key government installations, including Suluhu's heavily guarded offices in Dar es Salaam and Dodoma.

Human Rights Watch has decried a crackdown on activists, saying at least 10 people have been arrested since mid-November following social media posts about the planned protests.

"In the last couple of weeks, the government has sent a strong message that people should not go out into the streets and protest and express themselves about the violence that took place during the October 29th elections,” said Oryem Nyeko, a senior researcher in its Africa Division.

Nyeko said this is “very problematic” as people have a right to express themselves and to talk about things that concern them.

He said the organisation has documented a number of cases of people being picked up from their homes and off the streets by plain clothed men.

“In my opinion,” Nyeko said, “It is just a sign that Tanzanian authorities are increasingly intolerant of people's right to assemble."

Amnesty International also called on the authorities to respect and protect citizen’s rights to freedom of peaceful assembly and expression during the planned protests.

Last month, the government cancelled Independence Day celebrations, saying the funds would instead be used to repair damaged infrastructure.