Russia’s oil-product exports climbed to the highest since April on a four-week average basis, buoyed by a sharp rebound in fuel oil shipments.

Refined fuel flows averaged almost 2.7 million barrels a day in the four weeks to Dec. 31, according to data compiled by Bloomberg from analytics firm Vortexa Ltd. That’s about 152,000 barrels, or 6%, higher than the previous week.

The more volatile weekly flows rose slightly to 2.6 million barrels a day in the last week of December, even as diesel flows ebbed. Russian refinery rates were underwhelming last month, hampering the export of some key oil products.

The oil market is closely monitoring Russian oil flows to asses production since Moscow stopped releasing official output data. The country has pledged to cut exports by 300,000 barrels a day for crude and by 200,000 barrels a day for oil products in the first quarter, compared with the May-June 2023 baseline.

Here’s a breakdown of shipments from Russian ports for the week to Dec. 31: 

Diesel and gasoil exports fell roughly 4% from the previous week to a three-week low of 1.14 million barrels a day. Still, December’s total — at about 1.17m barrels a day — marked last year’s best month, helped by the easing of road fuel restrictions and as Black Sea ports recovered from storms.

The energy ministry is yet to fully remove all restrictions on winter-grade diesel exports. Shipments are allowed for fuels delivered to ports by pipeline and refiners need to keep at least 50% of their output at home. The nation plans to boost diesel flows by almost a fifth this month.

Naphtha shipments rebounded 23% to 326,000 barrels a day. Gasoline and blending component exports more than tripled to 157,000 barrels a day. No jet fuel shipments were observed for the week.

Fuel oil flows jumped by 64% to about 772,000 barrels a day, as shipments to Asia and Africa rebounded. Exports of refinery feedstocks like vacuum gasoil more than halved to 199,000 barrels a day.

Cargo volumes and destinations are likely to be revised if more port data or vessel information becomes available.