"Today … we launched a people's defensive war against the military junta," said Duwa Lashi La, acting president of the National Unity Government (NUG), in a video address posted to Facebook. He called on citizens "in every corner of the country" to revolt against military rule.
The NUG claims to be Myanmar's rightful government and has wide support in the country of 57 million. It consists largely of former lawmakers and others affiliated with Suu Kyi and her party, the National League for Democracy (NLD), who were ousted in the military coup.
Duwa Lashi La said his group also was calling on those working with the government, including civil servants, to abandon their posts and join the resistance. He ordered militias aligned with the shadow government to target the junta and its assets. The NUG's defense ministry also released a code of ethics for fighters, which included orders not to torture or sexually assault enemy troops.
The shadow government's intervention was largely celebrated by activists and civilians across Myanmar, who labeled the occasion "D-Day" against the military regime.
Within hours, student unions, militias and other armed groups signed on to the NUG's declaration, offering themselves as front-line fighters. Local media reported that junta forces clashed with armed ethnic groups in parts of the country, adding to fighting near the borders with Thailand and China. The declaration also appeared to reignite protests, which had largely quieted after the crackdown on peaceful demonstrators.
"People have been severely suffering at the hands of military terrorists," said Ko Htet Wai, an environmental activist who is part of the Bamar People's Liberation Army, a civilian militia. "Such a call for a defensive war by the NUG will encourage those who have been fighting the military separately to stand under one banner, and become a stronger force."
A resistance fighter who is training in the jungles of Myanmar said the declaration was an "alarm" for those like her.
"The junta is killing us, so we have to fight," she said, speaking on the condition of anonymity because of safety concerns. "This is such an honor for us."
A spokesman for the Myanmar military said that the armed forces were not worried about the declaration and that the NUG was posturing ahead of the United Nations General Assembly, where it is seeking recognition as the legitimate government of Myanmar. But witnesses saw fighter jets flying across parts of Myanmar, while security checks and troop deployments were stepped up in cities such as Yangon.
The military, known as the Tatmadaw, seized power Feb. 1, detaining Suu Kyi and others in the democratically elected NLD government whom it later charged with treason and other crimes. The military, led by commander in chief Min Aung Hlaing, claims that the NLD won elections last year fraudulently but has provided little evidence and has pledged to hold a new vote.
The coup ended a tenuous power-sharing deal between the generals and the civilian-led government, and returned Myanmar to direct military rule after a short experiment in nominal democracy. The resultant uprising has been met with lethal force and mass detentions by security forces, whose actions have been described by U.N. officials and human rights groups as crimes against humanity.
Both the security situation and trust in the military junta have deteriorated in recent months with the spread of the delta variant of the novel coronavirus, pushing Myanmar, its economy and health system toward collapse.
Richard Horsey, Myanmar adviser to the International Crisis Group, said that although the NUG's declaration "raised expectations that the revolution will now shift into higher gear," meeting those expectations will be difficult.
"The two sides are likely to remain locked in a violent stalemate, with neither able to easily prevail over the other," he said. "The backdrop of economic crisis, poverty and health system collapse mean that the consequences of the coup are devastating for ordinary people."
The international response to the crisis in Myanmar has largely been led by the Association of Southeast Asian Nations (ASEAN), which named an envoy to deal with the situation. The envoy, a diplomat from Brunei, has not been granted access to the country. Sanctions imposed by the United States and other Western nations have done little to change the situation on the ground. ASEAN and others have pushed for a cease-fire, but Myanmar's military has not honored promises to end hostilities.
Against this backdrop, increasing numbers of people in Myanmar have turned to violence. Tens of thousands are estimated to have completed military training in areas controlled by ethnic armies that have been fighting the Tatmadaw for decades in the country's border regions. The military is doing battle on multiple fronts, including against the new militias made up of civilians.
In his declaration of war, Duwa Lashi La said Myanmar's people, faced with military atrocities, have no choice but fighting.
"I believe that our neighboring countries, ASEAN countries, the United Nations and all other countries around the world understand that we do it out of necessity, based on our country's current situation," he said.
Cape Diamond and Kyaw Ye Lynn contributed to this report.