Hundreds of Afghan university students in the eastern city of Jalalabad took to the streets on Monday to protest the building of a Pakistani military gate in what the Afghan defence ministry says is inside Afghanistan.
The incident is the latest in rising tensions between the two sides, whose attempts to lure the Taliban to the peace table have stalled amid their feuding.
Pakistani support for the Afghan peace process is considered essential because of the two countries' long, porous border and Islamabad's history of supporting militant groups.
The protest was sparked by a statement on Sunday by Afghan President Hamid Karzai who ordered his top officials to take immediate action to remove the gate and other "Pakistani military installations near the Durand Line".
The Durand Line is the 1893 British-mandated border between the two countries. It is recognised by Pakistan, but not by Afghanistan.
Afghanistan maintains that activity by either side along the Durand Line must be approved by both countries.
"Establishing a gate by Pakistan on the Durand Line and inside Afghanistan is against all international norms," Afghan defence ministry spokesman, General Zahir Azimi, told a news conference on Monday.
"We will use all options to remove whatever they have built," he added, without elaborating.
That came on the same day as university students in the Surkhroad district of Nangarhar province demonstrated against the Pakistani gate.
Chanting "death to Pakistan", "death to ISI" and "death to (Pakistani President Asif Ali) Zardari", the students marched from Nangarhar university and blocked the main highway between Kabul and Jalalabad for about an hour.