Afghan National Army (ANA) soldiers march during a ceremony in a military base in the Guzara district of Herat province, Feb. 28, 2019. Getty

Kabul, Afghanistan -- Authorities are investigating an errant U.S. bombing of an Afghan military base in the country's south that killed at least five Afghan troops, a lawmaker said Thursday. The soldiers were killed by friendly fire Wednesday in what was supposed to be a precision airstrike by U.S. forces supporting Afghan soldiers battling insurgents near the city of Tarin Kot in Uruzgan province.

The Defense Ministry earlier said the fatalities were the result of a miscommunication between Afghan troops on the ground and forces in the air, without providing details.

Lawmaker Obaidullah Barikzai from Uruzgan province told The Associated Press that Afghan soldiers inside the base in Tarin Kot believed a darkened convoy approaching the base was the Taliban -- not U.S. and Afghan forces -- and opened fire, invoking a blistering retaliation.

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The Taliban often travel in convoys with no vehicle lights on, Barikzai said.

A U.S. airstrike was called in to aid the under-fire convoy, he added. It hit the Afghan army base, barely 2.5 miles from the governor's house and the shootout continued for hours as residents hunkered inside their homes.

The U.S. military said Wednesday it responded to incoming fire on Afghan and U.S. forces on the ground and attempted to come to their defense by conducting a precision airstrike.

"We are operating in a complex environment where enemy fighters do not wear uniforms and use stolen military vehicles to attack government forces," said the U.S. mission spokesman Bob Purtiman.

Barikzai said many of the wounded in the deadly incident were in critical condition but did not provide details.

In other developments, the Taliban slammed the U.S. State Department's 2018 human rights report, released Wednesday for singling out the Taliban for attacks against civilians. The report also took note of what it said were extrajudicial killings by Afghan security forces as well as the Kabul government's rampant corruption.

"The U.S. is an occupier country directly involved in crimes against humanity," said Taliban spokesman Zabihullah Mujahid. "The show of concern and sadness about human rights by such a criminal state is preposterous and comical."

Despite intensified negotiations between the U.S. and the Taliban to end the 17-year was in Afghanistan, the insurgents have been carrying out near-daily attacks across the country, mainly targeting the government and security forces and causing staggering casualties.

Meanwhile, in the capital of northern Balkh province, shops and businesses were closed in a city-wide strike to protest the appointment of a new provincial police chief over the objections of a former governor and powerful warlord.

The incumbent provincial police chief, Gen. Akram Sammeh, said his replacement, Abdul Raqib Mubarez, landed at the airport in Mazar-e-Sharif on Thursday but the police were blocking him from heading into the city to take up his post.

The development threatens to escalate into an all-out feud between Afghan President Ashraf Ghani and Atta Mohammed Nur, a powerful warlord who holds sway over Balkh province where Mazar-e-Sharif is the provincial capital.

Later Thursday, the standoff escalated into a firefight as Nur's militia surrounded the police headquarters in Mazar-e-Sharif, exchanging rocket fire with government forces, said the incumbent police chief Sammeh. There were no immediate reports of casualties.

Several years ago Afghanistan legalized militias loyal to the country's warlords, many of whom took up government positions after the overthrow of the Taliban. Initially, after the 2001 collapse of the Taliban, the United Nations ordered all militias disarmed but as the country's security deteriorated, many warlords both with the government and in opposition redeployed their militias.

Nur called for the city-wide shutdown and is demanding Ghani withdraw Mubarez's appointment and instead name Nur's choice for the post, as Ghani allegedly promised.