Disturbing news from Pakistan—the fourth wheel on the Axis of Evil—where the US has imposed sanctions on a key nuclear installation because it is helping “another country” develop WMD. (Hat tip: NC.)

Pakistan launched a nuclear missile from Kahuta Research Laboratories

The United States says a key nuclear installation in Pakistan has been helping another country in its programme of weapons of mass destruction.

A spokeswoman at the US embassy in Islamabad refused to name the country involved.

The US says it has imposed sanctions on the installation, a nuclear enrichment facility. But it has not given details of them.

Pakistan has strongly criticised the move, although it says it will not affect relations between the two countries.

The installation at the centre of the dispute is the Kahuta Research Laboratories (KRL) near the capital, Islamabad.

The US imposed the sanctions because of KRL’s “material contribution to the efforts of a foreign (non-US) country, person or entity of proliferation concern, to use, acquire, design, develop and or secure weapons of mass destruction, and/or missiles capable of delivering mass destruction,” the AFP news agency reports a US embassy spokeswoman in Islamabad as saying.

However, correspondents say it is not clear if these are fresh sanctions or the renewal of sanctions already in place.

In its first public comments on the issue on Monday, the US embassy said the sanctions came into force last week.

The Pakistani Foreign Ministry on Monday said the decision was unjustified.

It added that the restrictions would not affect the work of the nuclear installation at Kahuta.

It also appeared to contradict the US explanation for the move, saying it was because Pakistan had acquired material from another country - not because it supplied material to a third party.