An official of the Chaman administration, Zakaullah Durrani, told Reuters that the situation on the border remained tense.
The crossing, mostly closed to pedestrians during the COVID-19 pandemic, was briefly opened on Wednesday and was to open again Thursday to allow nationals of both countries to cross for Eid, which falls on Friday in Afghanistan and Saturday in Pakistan. Security forces fired aerial shots to disperse the protesters.
The Pakistani forces "acted only in self-defence", a statement read.
About 150 people had gathered at the crossing, many of them hoping to visit loved ones in Afghanistan for Eid al-Adha, said Mr Usman Ali, the commissioner for the Quetta border region.
"Pakistan is undertaking concerted efforts to ensure regulated movement of trade between the two countries, which are being challenged by elements opposed to such regulation", the Foreign Office explained.
Pakistan troops deployed on the posts were also simultaneously engaged by Afghan posts, it said.
The FO spokesperson Aisha Farooqui said in a media statement that Afghan forces had opened unprovoked fire on innocent civilians gathered towards Pakistan's side of the global border at the Friendship Gate Chaman on July 30.
"They tried to cross into Afghanistan by force and also damaged our posts, and unfortunately at the same time shots were fired from the other side".
One policeman was among the dead, with the rest of the casualties civilians, he said.
"This unfortunate incident resulted in numerous casualties and deliberate/serious damage to state infrastructure on the Pakistani side", it said.
Asghar Khan Achakzai, a member of the Balochistan legislature and leader of the Awami National Party from Chaman, told Radio Mashaal late on July 30 that he had telephoned the Afghan officials at the border, after which the two sides stopped firing.
Mohammad Akhlaq, a local police official, said after protesters set fire to the quarantine facility, troops wielding batons pushed back protesters. The military clash stopped once the Afghan side stopped firing. "We hope our constructive efforts will be reciprocated", it said.
Despite conciliatory signals from Pakistan, the Afghan side appeared aggressive, at least in its post-clash tone.
"Afghan forces opened unprovoked fire on innocent civilians gathered towards Pakistan's side of the worldwide border", read a statement issued by the Ministry of Foreign Affairs. "It is the responsibility of the government to provide employment to the people but there will be no compromise on security matters", he said.