A 12 October 2008 posting on Free Range International, a blog with some fascinating on-the-ground reports and thoughts from Afghanistan:

Two days ago, I traveled to Hairatan which is located approximately 65km north of Mazar-e-Sharif. It is also located on the Amu Darya river (formerly know as the Oxus River) which is the longest river in Central Asia. For someone like myself who has never operated any where else other than the southern or eastern parts of the country, it sure came across as a bit of a surprise.
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One of the most striking impressions that I got was seeing an operating freight rail system. After being to most corners of Afghanistan, and only witnessing ‘Jingle’ trucks and semi-trailers it was quite a sight to see a train in operation. The main purpose of the train is transporting fuel, which is imported from Uzbekistan.
Source: Free Range International

There are a couple of big pictures showing the Friendship Bridge and (presumably Uzbek Railways) locomotive TEM2-3315 in operation at Hayratan.