Germany's foreign ministry said Thursday that its embassy in Afghanistan was shut but declined to comment on a media report it had been closed in response to a security threat.

"It is correct that the German embassy in Kabul is currently closed," a foreign ministry spokesman told AFP, confirming a report in the Die Welt daily.

However, the spokesman would not be drawn on the Die Welt information that the embassy had been closed for "several days" after warnings of an "Islamist terrorist attack" from the German secret service (BND).

"According to our information, the BND recently warned the foreign ministry of a risk of a terrorist attack by Islamists in Kabul," wrote the daily.

The indications of a looming attack were "concrete" and "serious," added the paper.

With some 4,000 troops stationed in Afghanistan, Germany is the third-largest contributor to the NATO-led International Security Assistance Force.