Protesters have clashed with the police and ruling party activists in several parts of the country, triggering tension across the nation where disturbance began last month over quota in government jobs.

The protesters are demanding PM Sheikh Hasina to step down.

Hasina, the longest-serving PM of the country, was democratically elected to power for another term this year.

Demanding the PM to step down, the Anti-Discrimination Student Movement has called for a "March to Dhaka" programme on Monday, a move which can escalate tension.

Three coordinators of the movement -- Asif Mahmud, Sarjis Alam, and Abu Baker Majumder -- confirmed the programme to The Daily Star newspaper of Bangladesh.

In Sirajganj, 13 policemen were killed during an attack on Enayetpur police station.

According to police sources, some individuals attacked the police station in the afternoon. They entered the station, committed acts of vandalism and set fires, reported Dhaka Tribune.

The attackers, whose identities are not known so far, also beat 13 on-duty police officers to death.

The Bangladesh government has declared an indefinite nationwide curfew starting at 6 p.m. local time on Sunday.

It is the first step taken by the government to curb a fresh round of protest.

The government also announced a three-day general holiday from Monday.

In a bid to quell protests, the government has shut down internet services across the nation.

Sheikh Hasina described those behind the sabotage in the name of protest as terrorists.

“I appeal to the countrymen to suppress these terrorists with a firm hand,” she said in a meeting of the National Committee on Security Affairs at Ganabhaban on Sunday, according to sources from the Prime Minister's Office (PMO), reported Dhaka Tribune.

Hasina earlier blamed the opposition for capitalising on the situation and carrying out deadly attacks in the country.

Stipulating that 93 percent of recruitments will be on merit now, Bangladesh Supreme Court last month scrapped most of the quotas in government jobs that had led to massive protests in July.

India issues advisory

The Indian government on Sunday issued an advisory to citizens and strongly advised them against travelling to the country till further notice.

"All Indian nationals presently in Bangladesh are advised to exercise extreme caution, restrict their movements and remain in contact with the High Commission of India in Dhaka through their emergency phone numbers," read a statement issued by the Ministry of External Affairs.