扎兰季（波斯语：زرنج‎）位于阿富汗西南部，邻近伊朗边境，是尼姆鲁兹省的首府。

根据《旧唐书》记载，阿拉伯人在公元661年入侵波斯之时，卑路斯向当时统治中国的大唐要求提供军事协助。大唐于是成立波斯都督府于今日阿富汗的扎兰季市（Zaranj），并任命卑路斯为都督。公元670年到674年，卑路斯来到唐朝首都长安，并被封为右武卫将军。

678年，吏部侍郎裴行俭奉命送卑路斯返回波斯。不过裴行俭并没有送他到波斯，而是在碎叶（即今日吉尔吉斯的托克马克）折返长安。结果卑路斯和千多名随从在吐火罗逗留了超过20年。

Zaranj or Zarang (Persian/Pashto/Balochi:زرنج) is a city in southwestern Afghanistan, near the border with Iran, which has a population of 160,902 people as of 2015. It is the capital of Nimruz province and is linked by highways with Lashkar Gah to the east, Farah to the north and the Iranian city of Zabol to the west. Zaranj serves as the border crossing between Afghanistan and Iran, which is of significant importance to the trade-route between Central Asia and South Asia with the Middle East.