About a thousand demonstrators against last month’s military seizure of power in Myanmar emerged cautiously Tuesday onto the streets of the country’s second-biggest city, those in the vanguard carrying homemade shields bearing images of the three-fingered salute, the movement’s symbol of defiance.

The protest in Mandalay took place even though security forces have shown little reluctance to use lethal force to break up crowds. Those who marched gathered for just a few minutes before dispersing to avoid a possible confrontation with riot police. Another group made a mobile protest, driving through the streets on motorbikes.

The protesters have adapted their tactics in response to escalating violence from security forces, including the firing of live ammunition at crowds. The government’s crackdown has left more than 50 protesters dead but has failed to slow the widespread protests against the Feb. 1 coup that ousted the elected government of Aung San Suu Kyi.

A school principal involved in the protest movement died from unknown causes after being taken into custody by security forces, according to media reports and an activist who knew him.

The death of Zaw Myat Lin in custody was the second in recent days. He was a member of Suu Kyi’s National League for Democracy party.

The deaths of Zaw Myat Lin and Khin Maung Latt, a party activist who was detained on Saturday night whose body was retrieved from a military hospital the next day, have raised questions about whether the government is torturing and killing detainees. Witnesses said Khin Maung Latt’s body had wounds consistent with torture, according to New York-based Human Rights Watch.

Zaw Myat Lin was arrested Monday night as he tried to escape from a police raid, the Voice of Myanmar online news service and other media reported.

Maung Saungkha, an activist and friend of Zaw Myat Lin, said his family was summoned to retrieve his body on Tuesday and was not told how he died.

Nighttime hours have become increasingly dangerous. Police and army units routinely range through neighborhoods, shooting randomly to intimidate residents and making targeted arrests.

THOUSANDS ARRESTED

According to the Myanmar-based Assistance Association for Political Prisoners, more than 1,850 people have been arrested in connection with the coup. Dozens of journalists have been arrested, including Thein Zaw of The Associated Press, who has been charged under a public order law that carries a penalty of up to three years in prison.

In what has become a daily occurrence, protest marches were held Tuesday in cities and towns across the country, according to local news reports and social media.

Protests occurred in Ye, a town in Mon State in southern Myanmar; Kyaukpadaung, a town in central Myanmar; Mohnyin, a town in Kachin State in the north; and Myeik Taung, in the southeast. The authorities reportedly used force in each case.

Armed police carried out night patrols on Monday, yelling abuse, firing at buildings and making targeted arrests. The tactic appears to be aimed at spreading fear and disrupting sleep in order to weaken the resolve of those opposed to the army’s takeover.

The military government on Monday imposed a major curb on media coverage of the crisis. It announced that the licenses of five local media outlets — Mizzima, DVB, Khit Thit Media, Myanmar Now and 7Day News — had been canceled.

“These media companies are no longer allowed to broadcast or write or give information by using any kind of media platform or using any media technology,” it said on state broadcaster MRTV.