KABUL (Reuters) - Hundreds of Afghan families have been displaced by cross-border rocket and artillery fire by Pakistani troops, an aid group said on Monday, as tension rose after Pakistan said militants implicated in recent attacks had taken shelter in Afghanistan.

As many as 200 families have been displaced from their homes, while some civilian casualties have also been reported after Pakistani border troops fired rockets and artillery, according to the Norwegian Refugee Council (NRC).

Islamic State’s regional branch claimed responsibility for a bomb attack on Thursday at a Sufi shrine in Pakistan’s Sindh province. The toll in that attack has reached 90 people dead and more than 350 wounded, police said on Monday.

Pakistan said militants operating out of eastern Afghanistan were behind the attack.

Amid a security crackdown, border crossings were closed and Afghan diplomats were summoned to Pakistan’s military headquarters in Islamabad and given a list of 76 “most-wanted terrorists” that Pakistan said were in Afghanistan and demanded they be captured and handed over, the Pakistani army said.

Since then, Pakistan says it has killed “over 100 terrorists”, including some in camps inside Afghan territory in shelling on Friday and over the weekend.

On the weekend, the Afghan government summoned Pakistan’s ambassador to protest against the shelling and to express condolences for the shrine attack.

NRC’s country director in Afghanistan, Kate O’Rourke, said civilians have been caught in the cross-border firing.

“Whether indiscriminate or specifically targeted, such attacks forcibly displace civilians, violating international humanitarian law, and must stop,” she said in a statement.

Afghan officials said a number of special forces had been deployed to the border to counter any Pakistani raids.

“If they continue their attacks we will respond in kind,” said Attahullah Khogyani, a spokesman for Afghanistan’s eastern Nangarhar province.

In Asadabad, the capital of Afghanistan’s Kunar province, also on the border, hundreds of Afghans gathered to protest against Pakistan and to ask foreign governments to put pressure on it.

The uneasy neighbors have long traded accusations of harboring anti-government militants.

Afghanistan has for years complained that insurgent groups like the Taliban have found sanctuary in Pakistan. Afghanistan’s ambassador to Pakistan on Monday handed the Pakistan government a list of insurgents and camps suspected to be in Pakistan.

Pakistan’s army chief, General Qamar Javed Bajwa, said the two governments would work together to prevent cross-border movement by militant groups, the Pakistani government said in a statement.

On Friday, Afghan officials said government forces backed by international troops had killed two dozen Islamic State fighters in recent operations.

Islamic State forces, meanwhile, killed at least 18 Afghan soldiers at a checkpoint in Nangarhar on Thursday.