Human rights groups have criticised authorities in the Gambia after police arrested 137 people, injured dozens and detained prominent journalists amid protests calling for the president to honour a pledge to step down after three years in office.

Adama Barrow came to power after the election in 2016, ending 22 years of brutal dictatorship by Yahya Jammeh and inspiring widespread hopes for reform.

But the 54-year-old, a former businessman who once worked as a security guard in the UK, has reneged on a campaign promise to step down by this month, saying the constitution requires him to serve out a full five-year term.

In response, a movement called Three Years Jotna, which means “enough” in the local Wolof language, began protesting last month to demand his departure.

On Sunday, police intervened when protesters deviated from the planned route on the outskirts of the capital Banjul in order to march toward the city centre, the government said.

In a statement late on Sunday, government spokesman Ebrima Sankareh said the protesters had “became riotous and violent by obstructing roads and burning tyres and logs on the highway as well as setting up fires in nearby bushes and on government wetland”.

Images of the protests showed police firing teargas at protesters before charging them with batons. Witnesses said they heard chants inciting an uprising.

Eighteen police officers and seven civilians were injured in the clashes and some of the 137 arrested were executive members of Three Years Jotna,Sankareh said.

The government has also decided to ban Three Years Jotna, Sankareh said, calling it “a subversive, violent and illegal movement”, and suspended two radio stations it accused of inciting violence during demonstrations.

Opposition leaders could not be reached for comment.

Amnesty International said the crackdown on protesters had alarming echoes of the Gambia’s brutal past and would fuel tensions.

“There have been some significant improvements in the country’s human rights record since President Adama Barrow came to power, but the use of excessive force by security forces to disperse protesters risks fuelling tensions and steering the Gambia back to dark days of repression,” the campaign group said.

Sunday’s march follows earlier protests by hundreds of Gambians calling for justice over human rights violations and abuses, including forced disappearances, rape, and murder, which occurred during Jammeh’s 22-year rule.

There have also been previous demonstrations by Jammeh’s supporters in favour of the former dictator’s return from exile in Equatorial Guinea. Jammeh fled in January 2017 under military pressure from West African countries to respect his election loss to Barrow.

The government has said Jammeh will be arrested for killings, torture and other abuses allegedly committed by his security forces if he returns to the Gambia. Jammeh denies those allegations.

Ismaila Ceesay, a senior lecturer in political science at the University of the Gambia wrote on Twitter that the “disproportionate use of force by police against protesters, the shutting down of media houses & the arrest of journalists marks the dawn of a retreat from our democratic progress”.

Senior officials have previously said the agreement to stand down after three years of the five-year term was a result of Barrow being misled.

“He was misguided and misled into this [agreeing to serve for only three years]. There is no transitional president, he’s not a transitional president. He’s an elected president and executive president,” Barrow’s close adviser Seedy Njie told the Guardian last year. “When they made this agreement, there were a lot of politicians around him who were misguiding him. When he assumed office … he looked at the laws and he realised that he was elected to serve a period of five years.”

After winning plaudits at the beginning of his tenure for committing to respect rights and establish a truth commission to investigate abuses under Jammeh, Barrow is facing multiple challenges.

Critics say that not enough has been done to purge those involved in human rights abuses under the former dictator from the military, police and intelligence service, nor to reduce the size of the security establishment.

In July, dozens of protesters calling for better services in the city of Brikama were tear-gassed and hospitalised. The rapper Killa Ace, arrested with 36 others in August after protests against alleged police brutality, was held for weeks before being released on bail.

Barrow also faces a weak economy, hobbled by massive debts incurred by Jammeh’s government and soaring unemployment.