Iranian crude imports by the main Asian purchasers upped more than 30 percent in the first 5 months of 2017, government and ship-tracking data suggested.

China, India, South Korea and Japan - Irans top four Asian buyers - purchased 1.765 million barrels per day (bpd) in the 5-month period, up from 1.353 million bpd in the same period in 2016, Reuters reported.

China was the biggest buyer, importing 600,597 bpd. India, South Korea and Japan ranked next, importing 548,200 bpd, 444,185 bpd, and 172,974 bpd, respectively.

However, imports fell 2 percent in May from a year ago, marking the first year-on-year decline since January 2016, when Western sanctions were removed leading to a spike in Tehrans exports.

The top four Asian buyers imported 1.60 million bpd in May.

Iran was exempted from output cut, a decision made by the Organization of the Petroleum Exporting Countries as an agreement to reduce output by 1.2 million bpd that began this year.

Iranian oil minister Bijan Zanganeh stated earlier this month that overall Iranian oil output was hanging around at more than 3.9 million bpd and is expected to reach 4 million bpd by March 2018.