The South American country has plunged into political chaos following the resignation last week of President Evo Morales, with at least 17 people killed in demonstrations since then.
Michelle Bachelet, the UN rights chief, said while earlier deaths mostly resulted from clashes between rival protestors, the latest incidents appear to be due to the disproportionate use of force by the army and police.
With the country divided, she fears the situation could worsen.
“I am really concerned that the situation in Bolivia could spin out of control if the authorities do not handle it sensitively and in accordance with international norms and standards governing the use of force, and with full respect for human rights,” she said in a statement issued on Saturday.
“The country is split and people on both sides of the political divide are extremely angry. In a situation like this, repressive actions by the authorities will simply stoke that anger even further and are likely to jeopardise any possible avenue for dialogue.”
Widespread arrests inflaming tensions
Ms. Bachelet is also concerned that widespread arrests and detentions are adding to the tensions. More than 600 people have been detained since 21 October, many in the past few days, according to her office.
The UN Secretary-General has dispatched his Personal Envoy in efforts to bring about a peaceful resolution to the crisis.
“This situation is not going to be resolved by force and repression,” she said. “All sectors have the right to make their voice heard – this is the basis for democracy.”
Ms Bachelet called for prompt, transparent and impartial investigations into the arrests, detentions, injuries and deaths that have occurred as a result of the crisis.
Data on these incidents also should be made available, she added.