THE HAGUE, Netherlands (AP) — Two suspected letter bombs exploded early Wednesday in the Netherlands, police said. Nobody was injured in the blasts.

One of the explosions happened at a business in Amsterdam and the other at a mail sorting office in the southern city of Kerkrade, police said in tweets. It wasn't immediately clear if the two explosions were linked.

Last month, letter bombs were sent to several businesses in the Netherlands, followed by a warning letter, police said. They didn't reveal details about the warning letters.

There have been no arrests announced in the investigation into those explosive devices, none of which went off, and police haven't given details about a possible motive.

It wasn't clear Wednesday if the two explosions were linked to the letter bombs mailed in January.