QUETTA, Pakistan — Pakistani troops opened fire on Thursday during a rally by minority Pashtun laborers demanding the reopening of a border crossing with Afghanistan, killing at least three people and wounding 13, human rights activists said.

The police denied that and said the protesters attacked a checkpoint at the Chaman border crossing.

The demonstrators — mainly workers from the Pashtun minority trying to get to Afghanistan for work — had rallied near the crossing, demanding authorities lift the months-long closure of the border related to measures meant to curb the spread of the coronavirus.

Witnesses say gunshots were heard when protesters tried to cross the border by force and torched a makeshift facility set up there to quarantine COVID-19 patients.

After the initial border closure in March, the crossing reopened during daylight hours but remained closed for wage laborers who travel to Afghanistan by day and return home by the evening.

Footage taken by Pashtun activists and released on social media shows smoke at the border crossing and people in hospital beds in the town of Chaman.

According to police, the protesters, backed by the Pashtun Protection Movement, known for its criticism of the Pakistani army, stormed a border checkpoint. Farhatullah Babar, a prominent Pakistani activist, demanded an investigation.

Mohammad Akhlaq, a local police official, said after protesters set fire to the quarantine facility, troops wielding batons pushed back protesters. Gunshots were heard amid the chaos

The provincial home minister, Mir Ziaullah Longove, told a news conference after the incident that the police did not open fire at the protesters, and insisted instead that there had been armed men among the rally who opened fire toward the troops.

So far, Pakistan has reported more than 277,000 cases of the new coronavirus and 5,924 deaths, including 32 in the past 24 hours.