A strong early morning earthquake in Italy has killed at least 27 people, and left thousands homeless.

Italian officials say four children are among the dead and others are missing after Monday's earthquake that shook central Italy, including Rome.

The children were killed in the town of Aquila when their house collapsed.

The U.S. Geological Survey says the quake registered a magnitude of 6.3.  

Rescue workers are searching for victims along rubble-strewn streets in Aquila, where a church dome and a dormitory collapsed. People are reported to be trapped in the university residence.

Prime Minister Silvio Berlusconi has declared a state of emergency.

Italy's Civil Protection Department says the quake was centered near Aquila, east of Rome, in the mountainous Abruzzo region.  

Monday's quake occurred about five hours after a 4.6 magnitude temblor shook Italy's north central region near Ravenna in the Emilia-Romagna region.  

Public safety officials say that quake was exceptionally deep at 28 kilometers.

Earthquakes can be particularly dangerous in Italy where there are many centuries-old buildings, some in poor repair. 

Some information for this report was provided by AFP, AP and Reuters.