Pakistan's embassy in Kabul said on Sunday that it was indefinitely closing its consular office in the Afghan capital because of security reasons, amid mounting tension between the neighbouring countries.
Closure of the visa section will come as a huge blow for many Afghans, hundreds of whom apply daily for permits to travel to Pakistan where they seek medical treatment, goods and university educations.
An embassy spokesman said the consular section would be closed as of Monday "until further intimation".
The spokesman told AFP that the section typically processes about 1,500 visa applications a day.
In Islamabad, the Foreign Ministry said the Afghan charge d'affaires had been summoned to "convey serious concerns over the safety and security of the diplomatic personnel of the embassy of Pakistan, Kabul, and its sub-missions".
The ministry said embassy staff were being harassed.
"They were obstructed on the road and the embassy vehicles were also hit by motorcycles while going towards the embassy," it said.
Protests outside the Pakistani embassy are common, sometimes triggered by people unhappy about visa wait times or security while standing in long queues.
Relations between Afghanistan and Pakistan have long been fraught, with Afghans blaming Islamabad for any number of woes and accusing it of supporting the Taliban.
Pakistan denies it helps the insurgent group.
Tension increased in recent days amid clashes along the border in Afghanistan's eastern province of Kunar.
Both sides have accused each other's troops of cross-border shelling.
The Pakistani foreign ministry said six Pakistani troops were wounded on October 27 and 28 in "unprovoked mortar and heavy weapon firing" by Afghan soldiers.
Pakistani consular services remain open in Herat, Jalalabad and Mazar-i-Sharif, according to an embassy spokesman, who recommended that applicants travel to Jalalabad if they needed a visa urgently.