Spurning an appeal by the United Nations to top using lethal force against peaceful demonstrators, security forces in Myanmar on Thursday fatally shot at least 10 people protesting against last month's military coup.

The military also lodged a new allegation against Aung San Suu Kyi, the elected leader it ousted on Feb. 1. It charged at a news conference in the capital, Naypyitaw, that in 2017-18 she was illegally given $600,000 and gold bars worth slightly less by a political ally, former Yangon Division Chief Minister Phyo Min Thein.

Military spokesman Brig. Gen. Zaw Min Tun said Phyo Min Thein had admitted giving the money and gold to Suu Kyi, but presented no evidence.

The accusation was clearly aimed at discrediting Suu Kyi, and perhaps charging her with a serious crime. She and President Win Myint are both being detained on less serious allegations.

Myanmar has been roiled by protests and other acts of civil disobedience since the coup toppled Suu Kyi's government just as it was to start its second term. The takeover reversed years of slow progress toward democracy in the Southeast Asian nation after five decades of military rule.

Local press reports and posts on social media on Thursday said there were six deaths in Myaing, a town in the central Magway Region, and one each in Yangon, Mandalay, Bago and Taungoo. In many cases, photos of what were said to be the bodies of the dead were posted online.

Security forces have attacked previous protests with live ammunition as well, leading to the deaths of about 60 people. They have also employed tear gas, rubber bullets, water cannons and stun grenades. Many demonstrators have been brutally beaten.

In New York, the UN Security Council on Wednesday unanimously called for a reversal of the military coup and strongly condemned the violence against peaceful protesters. It also called for "utmost restraint" by the military.

A presidential statement approved by all 15 council members was formally adopted at a virtual meeting. The British-drafted statement calls for the immediate release of government leaders including Suu Kyi and Win Myint. It supports the country's democratic transition and ``stresses the need to uphold democratic institutions.''

The human rights group Amnesty International on Thursday issued a report saying Myanmar's military "is using increasingly lethal tactics and weapons normally seen on the battlefield against peaceful protesters and bystanders across the country."

The London-based group said its examination of more than 50 videos from the crackdown confirmed that "security forces appear to be implementing planned, systematic strategies including the ramped-up use of lethal force. Many of the killings documented amount to extrajudicial executions."

"These are not the actions of overwhelmed, individual officers making poor decisions. These are unrepentant commanders already implicated in crimes against humanity, deploying their troops and murderous methods in the open," Joanne Mariner, its director of crisis response, said in a statement.

As widespread street protests against the coup continue, the junta is facing a new challenge from the country's ethnic guerrilla forces, which until recently had limited themselves to verbal denunciations of last month's coup.

Reports from Kachin, the northernmost state, said guerrilla forces from the Kachin ethnic minority attacked a government base on Thursday and were in turn attacked. The armed wing of the Kachin political movement is the Kachin Independence Army, or KIA.

"This morning in Hpakant township, the Kachin Independence Organization (KIO/KIA) attacked a military council battalion based in Sezin village, and the KIO/KIA's Hpakant-based 9th Brigade and 26 battalions were attacked by helicopter. Both sides are still investigating," The 74 Media reported on Twitter.

A Facebook page for the Kachin Liberation Media said the KIA had overrun the government outpost and seized ammunition. It warned the government against using lethal force to break up anti-coup protests in the Kachin capital, Myitkyina, where two demonstrators were killed this week.

The reports could not be independently confirmed, and ethnic guerrilla armies as well as the government often release exaggerated information. However, even making such an announcement amounts to a sharp warning to the government.

The Kachin actions come a few days after another ethnic guerrilla force belonging to the Karen minority announced it would protect demonstrators in territory it controlled. The Karen National Union deployed armed combatants to guard a protest in Myanmar's southeastern Tanintharyi Region.

Myanmar has more than a dozen ethnic guerrilla armies, mostly in border areas, a legacy of decades-old struggles for greater autonomy from the central government. Many have formal or informal cease-fire agreements with the government, but armed clashes still occur.

There has been speculation that some ethnic groups could form a de facto alliance with the protest movement to pressure the government. (AP)