The country has been in turmoil since the military removed civilian leader Aung San Suu Kyi on February 1.

Myawaddy Bank's biggest branch in Mandalay was targeted on Sunday morning and a security guard was injured in the explosion, according to local media.

There was a heavy security presence in the area following the blast.

The bank is one of scores of military-controlled businesses that have faced boycott pressure since the coup, with many customers demanding to withdraw their savings.

There has been heavy bloodletting in recent days.

On Saturday a local monitoring group said security forces gunned down and killed 82 anti-coup protesters the previous day in the city of Bago, 65 kilometres (40 miles) northeast of Yangon.

AFP-verified footage shot early Friday showed protesters hiding behind sandbag barricades wielding homemade rifles, as explosions were heard in the background.

The United Nations office in Myanmar tweeted late Saturday that it was following the bloodshed in Bago, where it said medical treatment had been denied to the injured.

Overall the Assistance Association for Political Prisoners has verified 701 civilian deaths since the putsch.

The junta has a far lower number: 248, according to a spokesman Friday.

Despite the bloodshed, protesters continued to rally in parts of the country.

University students and their professors marched through the streets of Mandalay and the city of Meiktila on Sunday morning, according to local media.

Some carried stems of Eugenia flowers -- a symbol of victory.

In Yangon, protesters carried a banner that read: "We will get victory, we will win."

Protesters there, as well as in the city of Monywa, took to writing political messages on leaves including "we must win" and calling for UN intervention to prevent further bloodshed.

Across the country people have been urged to participate in a torchlight protest in their neighbourhoods after sunset on Sunday night.

-- Death penalty returns --

Unrest also erupted Saturday in the northwestern town of Tamu, near the Indian border, where protesters fought back when soldiers tried to tear down makeshift barricades erected to block security forces.

Two civilians were killed when soldiers started randomly shooting, said a local, with protesters retaliating by throwing a bomb that exploded and overturned a military truck, killing more than a dozen soldiers.

"Some are in hiding -- we are worried that our people will be hurt as a reprisal," the resident told AFP.

The mounting bloodshed has also angered some of Myanmar's 20 or so armed ethnic groups, who control swathes of territory mostly in border regions.

There were clashes Saturday in northern Shan state, as the Ta'ang National Liberation Army (TNLA), an ethnic rebel group, mounted a pre-dawn attack on a police station, said the TNLA's Brigadier General Tar Bhone Kyaw, who declined to give details.

Local media reported more than a dozen police officers were killed, while the TNLA said the military retaliated with air strikes on its troops, killing at least one rebel soldier.

State-run television reported in the evening that "terrorist armed groups" attacked the police station with heavy weaponry and set it on fire.

Meanwhile, state media reported Friday that 19 people had been sentenced to death for robbery and murder by a military court, with 17 of them tried in absentia.

They were arrested in Yangon's North Okkalapa township -- one of six areas in the commercial hub currently under martial law, meaning anybody arrested there is tried by a military tribunal.

Myanmar has long had the death penalty, but has not carried out an execution in more than 30 years, said Phil Robertson, deputy director of the Asia division for Human Rights Watch.

"It indicates the military are prepared to go back to a time when Myanmar was executing people," he said.