ISLAMABAD - At least 25 mortar shells fired from the Afghan soil landed in the border area of Ghulam Khan in North Waziristan Agency on Friday, Pakistani officials said on Saturday.

The Afghan online newspaper Khaama Press quoted sources as saying that the shelling continued for four hours.

The sources confirmed the shelling by unidentified people, believed to be Afghan security personnel, did not inflict any casualties to local residents.

The mortar shells were fired from Tarkhobi area in Afghanistan’s Khost province.

Cross-border shelling has heightened tension between Pakistan and Afghanistan as the two countries accuse each other of firing. The Afghan govt has repeatedly asked its Pakistani counterpart to stop cross-border shelling, the Pakistani officials, however, deny any involvement and blames Afghanistan for violating border sovereignty.