ISLAMABAD - Human rights watchdog Amnesty International has called on Pakistan to resolve hundreds of cases of enforced disappearances for which “no one has ever been held accountable”.

“Disappearances are a tool of terror... if committed as part of a widespread or systematic attack, they constitute a crime against humanity,” a statement issued by the rights watchdog Monday said, calling on Pakistan to “take concrete steps to end impunity”.

Pakistan has had a history of enforced disappearances over the past decade, mainly confined in the past to conflict zones near the Afghanistan border or to Balochistan.

However in recent years a growing number of such abductions have taken place brazenly in major urban centres such as Karachi, Lahore and even Islamabad.

Earlier this year award-winning Pakistani journalist Taha Siddiqui, who criticised the role of the military in Pakistan, managed to escape an attempted abduction in broad daylight on a busy Islamabad highway. He has since left the country.

Reporting critical of security policies controlled by the powerful military is considered a major red flag, with Siddiqui the most high-profile recent example among the many reporters who have been at times detained, beaten and even killed. Security agencies routinely deny being involved.

Last year, five social media activists who had been critical of the military as well as extremism were also disappeared, with their abductions sparking nationwide protests. Four were released within weeks, but the fate of the fifth remains unknown.

Many other people are believed to still be in custody. According to Amnesty, the United Nations has more than 700 such cases pending in Pakistan, while a state commission of inquiry into enforced disappearances lists hundreds of additional cases.

Victims include bloggers, journalists, students, peace activists and other human rights defenders.

Few punishments, Amnesty said, are “as cruel and deliberate.... Families are plunged into a state of anguish, trying to keep the flame of hope alive while fearing the worst. They may be in this limbo for years”.

According to the NGO, Pakistan has recently accepted UN recommendations that make enforced disappearances a crime but has refused to ratify an international convention protecting anyone from enforced disappearances.