Former Afghan president Hamid Karzai has accused Pakistan of trying to create “anarchy and weakness” in Afghanistan, following a deadly airstrike on Kabul.

In an interview with UK’s Sky News, Karzai said Islamabad’s policies were aimed at keeping Afghanistan unstable and “downtrodden,” warning that such an approach would harm both countries.

He condemned the recent strike on a drug rehabilitation hospital in Kabul, which Afghan officials say killed around 400 people, describing it as an “extremely unfortunate event” in the history of relations between the two neighbours.

Karzai said he personally heard the explosion, describing a “horrific sound” that shook his home and filled the surrounding area with smoke and dust.

The former leader, who governed Afghanistan from 2002 to 2014, said tensions between the two countries are longstanding, claiming Pakistan has struggled to maintain stable relations with successive Afghan governments.

He urged Pakistani leaders to change course and pursue a more constructive relationship, saying past strategies of interference and destabilisation had failed and would not succeed in the future.

Fighting between the two countries has intensified since late February, when Pakistan launched airstrikes it says targeted militant infrastructure. The United Nations estimates the violence has displaced more than 100,000 people.

Pakistan has denied targeting civilians, insisting its operations were aimed at militant sites and accusing Kabul of spreading “misleading” claims to deflect from alleged cross-Durand Line threats.