Yes it is a custom in the East just like here we shake hands or hug. Its not like being intimate or anything. The way things have changed in this day and age, at least here, it could be very misunderstood now. I don't know if it is as common as used to be in the East.
When spoken in the Bible it was speaking of our brothers and sisters in Christ. We are like a family even though it is in a spiritual sense. And it would just be like our natural family, our brother and sister that we love.