Bangladeshi authorities intercepted, detained and forcibly returned Rohingya civilians fleeing along their border with Myanmar despite ongoing fighting between Myanmar's security forces and Rohingya militias.

Hours before the Muslim-majority Bangladesh pushed back some 70 migrants, Myanmar's troops fired mortars and machine guns at villagers fleeing violence in the western Rakhine state.

The villagers were caught inside Bangladesh en route to a border refugee camp in Kutupalong, where thousands of Rohingya refugees already live in squalid conditions. Police said some of those detained had entered Bangladesh via the Ghumdhum border area, where Myanmar forces are currently engaged in an operation against armed militias.

"All 70 were detained and later pushed back to Myanmar by the border guards," local police chief Abul Khaer told the Agence France-Presse news agency.

"They were pleading with us not to send them back to Myanmar," one policeman told AFP on condition of anonymity.

Still stranded

Hundreds of Rohingyas are still stranded at the Naf river along the border with Bangladesh. The South Asian country's authorities say they have a "zero tolerance” policy for Rohingyas entering Bangladesh.

Sunday's assaults come a day after violence broke out in western Rakhine state when around 100 armed Muslim insurgents attacked security guards in the border region with Bangladesh.

The death toll from those attacks climbed to more than 100, according to Myanmar's army. Thousands of people are continuing to flee the area fearing an escalation in violence.

Escalating communal tensions

The Rohingya, an ethnic minority in Myanmar, have long complained of religious and cultural discrimination at the hands of the majority Buddhist people. About 10 percent of the world's stateless people live in Myanmar and Rohingyas make up the single largest stateless community in the world.

Read more: Myanmar leader Suu Kyi denies ethnic cleansing of Rohingya Muslims

The communal conflict has taken a violent turn in the past few years, with reports of a fast-growing radicalization among Rohingya Muslims.

In October last year, Rohingya militants attacked several security checkpoints and killed scores of police officers. Myanmar's security forces responded by launching counterterrorism operations against insurgents. Human rights groups, such as Human Rights Watch and Amnesty International, said these operations involved arbitrary killings, systematic rapes, the burning of houses and forced expulsions of locals.

According to the United Nations, around 87,000 Rohingyas have fled to Bangladesh following the start of the latest crisis in October. Bangladeshi authorities have taken a hard line with Rohingya refugees, attempting to limit their numbers in their country.