(CNN)At least 23 people have been killed, several more are missing and hundreds have been injured after an earthquake struck Albania on Tuesday.

The quake, which had a preliminary rating of 6.4 magnitude, hit the European nation at an approximate depth of 20 kilometers (12 miles) early Tuesday local time, according to the United States Geological Survey. It is the strongest to hit Albania in 40 years.The epicenter was in the port city of Durres,