A fake news story touched off a tense Twitter confrontation between nuclear power Pakistan and Israel, widely believed to have a nuclear arsenal of its own, in an episode that underlines the potentially harmful impact of such stories on sensitive global affairs.

In an apparent response to a fake story claiming Israel's former defence minister threatened a nuclear attack against Pakistan if it sends troops to Syria, Pakistani Defence Minister Khawaja Mohammad Asif reminded Israel that "Pakistan is a nuclear state too."

Israeli def min threatens nuclear retaliation presuming pak role in Syria against Daesh.Israel forgets Pakistan is a Nuclear state too AH —@KhawajaMAsif

Israel's Defence Ministry tweeted back Saturday, saying the original story on the site AWD News was "totally fictitious."

<a href="https://twitter.com/KhawajaMAsif">@KhawajaMAsif</a> reports referred to by the Pakistani Def Min are entirely false —@Israel_MOD

AWD has been identified by fact-checking organizations as a site that often propagates fake news.

Israel maintains a policy of nuclear ambiguity, neither confirming nor denying the existence of an arsenal. Pakistan became a nuclear power in 1998. The countries have no diplomatic ties.

There was no immediate reaction from Pakistan to Israel's response.