Chaman Civil Hospital's medical superintendent, Dr Akhtar, told DawnNews that five children and three women were among those killed, whereas police confirmed that four Frontier Corps (FC) personnel are among the injured.
Dr Akhtar added that over 40 people had been injured, with five critically wounded victims sent to Quetta for medical treatment.
In a press statement issued Friday afternoon, the Army's media wing said the exchange of firing had stopped and Pakistan and Afghan security officials would be meeting on the Chaman crossing for a flag meeting.
The director generals of military operations of both armies also established hotline contact ahead of the flag meeting.
The Army said Maj Gen Sahir Shamshad Mirza had condemned Afghan forces' unprovoked firing on Pakistani villagers and security forces while underlining to his Afghan counterpart that the Pakistani forces and civilians who had been attacked were well within Pakistani territory when assaulted.
He also asked the Afghan DGMO to limit their forces to their own side of the border and defuse the situation.
The Chaman border had been closed soon after the hostilities started.
Chaman city was also shut down following the attack, with shopkeepers shuttering their shops and residents evacuating their homes in Killi Luqman, Killi Jahangir and Badshah Adda Kahol, Killa Abdullah's district police officer (DPO), Sajid Mohmand, said.
Security had also been ramped up in Quetta and other parts of Balochistan following the cross-border attack, and additional contingents of the Army and FC had been dispatched to the Pak-Afghan border in Chaman, DawnNews reported, quoting military sources.
The Foreign Office (FO) also summoned the Afghan chargé d'affaires to lodge a protest against the cross-border attack.
The chargé d'affaires was told that the "unprovoked firing by Afghan forces had led to the loss of lives, disrupted the census in areas on the Pakistan side of the border and caused damage to properties," a statement released by the FO said.
The FO urged the Afghan government to take action against those responsible for the violation.
Samim Khpalwak, spokesman for the governor of Afghanistan's Kandahar province, in a statement to AFP said that one Afghan civilian and three border police forces personnel were also wounded in the exchange of fire.
He added that the scuffle was ongoing, with "dozens" of Afghan security forces rushing to the scene.
'Afghanistan was informed of census'
Inter-Services Public Relations (ISPR) had earlier released a statement saying the Afghan border police opened fire on FC personnel detailed for the security of a census team in Chaman despite the fact that Afghan authorities had been informed in advance about the census exercise in Pakistan and coordination was carried out through diplomatic and military channels.
"Since April 30, Afghan Border Police had been creating hurdles in [the] conduct of census in divided villages of Killi Luqman and Killi Jahangir in Chaman area, on Pakistani side of the border," the military's media wing said.
FO Spokesperson Nafees Zakaria during a weekly briefing in Islamabad also confirmed that Afghan authorities had been informed about the on-going census exercise.
Zakaria said that the census team "was fulfilling its duties in the area and the exercise was taking place within the jurisdiction of Pakistan."
The Kandahar governor's spokesman, Khpalwak, however, claimed that Pakistani officials had strayed on to the Afghan side of the border and were attempting to count people living there.
The FO added that Pakistan the right to retaliate after the exchange of fire, but said that Pakistan’s efforts for peace in Afghanistan would continue.
"Dialogue is the only political means available to us to establish peace in Afghanistan," Zakaria said.
During the cross-border "attack", mortar shells fired from the Afghan side had hit houses in a village of Killi Luqman, leaving one person dead and many others injured, Station House Officer (SHO) Chaman Maqsood had initially said. At least three children were among the injured, he had said.
He said the injured were shifted to the Civil Hospital Chaman, where an emergency has been imposed. Four of the injured are said to be in critical condition.
One of those slain was identified as 17-year-old Mohammad Ashraf.
"We were sleeping when we suddenly heard firing and blasts," Haji Ayub, a resident of Killi Jahangir told DawnNews. "We immediately left our houses and came to Chaman bazaar."
Abdul Mateen, a resident of Killi Luqman said FC personnel were guarding the census staff in his village when the Afghan forces opened fire on them.
"I lost a close relative in the attack," he said.
Exchange of fire at Torkham
Later in the day, an exchange of fire was reported at two check posts at Torkham Border between Pakistan and Afghan armed forces, DawnNews reported while quoting military sources.
According to the details shared by the officials, Afghan forces kept firing at Iqbal Post and Post II at Torkham Border for at least an hour. Pakistan also retaliated to the firing, they further claimed.
Meanwhile, the political administration said that a curfew was implemented in Khyber Agency following the exchange of fire at Torkham Border.
Pakistan had closed its borders with Afghanistan at Chaman and Torkham on Feb 18 after a series of terrorist attacks in the country killed over 100 people. Militants having sanctuaries in Afghanistan were blamed for the attacks.
After over a month of closure, Prime Minister Nawaz Sharif had ordered the reopening of the borders as a goodwill gesture.
The latest violence at Pak-Afghan border has come days after the visits of two high-profile Pakistani delegations to Afghanistan aimed at easing the tensions between the neighbouring states.
Speaking to the media upon his return from Kabul, NA Speaker Ayaz Sadiq had said that the Afghan leadership had "promised" that the Afghan president and the country's Chief Executive Abdullah Abdullah would visit Pakistan.
Earlier this week, Afghan President Ashraf Ghani declined invitations extended by top civil and military officials to visit Pakistan, saying he would not visit until Islamabad hands over the perpetrators of terror attacks in Afghanistan.