The Swiss foreign ministry has confirmed that a bomb was planted in its embassy in Poland on Monday, but says it has no idea as to the motive or identity of the perpetrator.
A spokeswoman in Bern, Daniella Stoffel, said no warning had been issued and no-one had claimed responsibility. She said Polish police were investigating.
The device was discovered by the janitor in the waiting room, after the embassy had closed on Monday. It was packed with about one kilogramme of explosive and filled with nails.
Stoffel said experts from the Polish interior ministry set it off in a controlled explosion, causing very little damage.
She said the embassy had operated normally on Tuesday.