112 is used as an international GSM emergency number.
Quote from above link:
"The GSM mobile phone standard includes 112 as an emergency number, and in countries where 112 is not the standard emergency telephone number, GSM telephone users who make calls to 112 generally have their calls redirected to the local emergency telephone number, if it exists. This is valuable for foreign travelers, who may not know the local emergency number. Most GSM mobile phones can dial 112 calls even when the phone keyboard is locked, the phone is without a SIM card, or instead of the PIN."
I have never understood how on my old phone if I was not in an area without good reception a message would come up on the display saying "Emergency use only". If there is no reception how would an emergency call work???