Qamishli, Syria – The U.N. says 70,000 people in northern Syria have been forced to flee because of Turkey's assault on U.S.-backed Kurdish forces. Turkish warplanes and artillery blasted targets across the Syrian border Friday on the third day of the offensive.

The city of Qamishli in northern Syria is a very important city for the Kurdish population, reports CBS News correspondent Charlie D'Agata. It sort of serves as their administrative center. But it's is only about a mile and a half from the Turkish border, which means it's vulnerable to airstrikes, artillery and mortars.

A couple of nights ago, Qamishli came under a mortar attack. Three mortars slammed into the neighborhood, killing one person on the spot. Two people were injured and are now fighting for their lives in a hospital.

This kind of random violence in the area has sparked a mass exodus of Qamishli. There was a bottleneck Thursday on a main road leading south, away from Turkish airstrikes and mortar attacks. Families didn't want to take a chance with their young children on attacks like this.

The Turkish government has defended its military operation, saying it's clearing the area of terrorists. But more and more, it's starting to look like a campaign of ethnic cleansing – forcing the local Kurdish population away from cities and villages. Instead they're putting in place many Syrian Arabs who sought refuge in Turkey, people who don't come from the region. That has now become a point of discussion not only among the local population, but also among the international community.