An estimated 6.1 magnitude aftershock rocked the already earthquake ravaged country of Haiti Wednesday morning, shaking buildings and sending people into the streets.

The new quake was the largest aftershock yet to follow last week's magnitude 7.0 quake that shattered Haiti. It hit about 35 miles northwest of the capital of Port-au-Prince and 13.7 miles below the surface. It is not yet clear the amount of damage the aftershock caused.

Meanwhile, search and rescue teams continue to pull survivors from the rubble of last week's quake. Tuesday, they rescued a 25-year-old woman from the remains of a collapsed supermarket.

Authorities said rescue teams have pulled close to 100 people out of destroyed buildings since the quake hit. The quake killed an estimated 200,000 people and left a quarter million with injuries.

The World Food Program estimates that 3 million people need aid. So far, it has distributed more than a quarter million ready-to-eat meals.

Meanwhile, the U.S. Marine 22nd Expeditionary Unit is on the ground Wednesday helping with the relief effort.