PORT AU PRINCE – A quake measuring 7.0 on the moment magnitude scale rocked the impoverished Caribbean nation of Haiti Tuesday causing panic as it struck, officials and AFP witnesses said.

A tsunami alert was immediately issued for the Caribbean region after the earthquake struck at 2153 GMT. An AFP correspondent said it lasted more than a minute.

The US Geological Survey said the powerful quake was initially measured at 7.3 on the scale and struck 14 kilometres (nine miles) from the city of Carrefour, and 27 kilometers (17 miles) from Petionville.

An AFP correspondent in Petionville said one three-story building was toppled, and a tractor was already at the scene trying to dig out victims as people fled onto the streets in panic.