Feb. 12 (UPI) -- Letter bombs exploded Wednesday in two locations in the Netherlands, though police said they're not sure if the blasts are connected.
Investigators said no one was injured in either blast.
The first explosion happened around 8 a.m. in the mailroom of a business in Amsterdam. The police department there said a letter accompanied the letter bomb that requested a payment in bitcoins.
The department described the letter as extortion. They called on people to report suspicious letters, especially those that may be in thick, white envelopes with an address printed on paper covered in plastic.
The second blast happened around 9 a.m. in the southern Dutch town of Kerkrade near the German border. The letter arrived at a business, where an employee heard a "strange noise" from the package before it exploded. All employees at the building were evacuated.
The local police department described the damage in the building as "limited."
Officials said they were investigating whether the two explosions were related.