A very powerful aftershock shook the Haitian capital Port-au-Prince at around 1100 GMT Wednesday, a week after a 7.0-magnitude earthquake killed thousands in the Caribbean nation, DPA reported.
The US Geological Survey said the aftershock measured 6.1 on the Richter scale, with its epicentre some 60 kilometres west of the capital.
There were no immediate reports of casualties or damage.