Russian crude oil shipments dropped to a two-month low as loadings from Russia’s Western ports slumped, tanker-tracking data monitored by Bloomberg showed on Tuesday.

In the four weeks to November 17, Russian crude oil exports by sea dipped to 3.28 million barrels per day (bpd), down by 150,000 bpd compared to the previous four-week average to November 10, according to the data reported by Bloomberg’s Julian Lee. The decline in exports was the biggest since the end of July.  Daily crude flows in the week to Nov. 17 slumped by about 740,000 barrels to 2.83 million, dropping to their lowest since the first seven days of July.

The decline was driven by lower flows from the country’s Baltic, Black Sea and Arctic ports, while shipments from the Pacific remained unchanged.

A total of 26 tankers loaded 19.8 million barrels of Russian crude in the week to Nov. 17, vessel-tracking data and port-agent reports show. The volume was down sharply from a revised 24.98 million barrels on 32 ships the previous week.

The weekly decline was mostly the result of a 30% slump in shipments from Russia’s export terminals on the Baltic and Black Seas. It could have been the result of increased refining rates in the second week of November, which left lower volumes of crude available for exports, according to Bloomberg.

In October, as available refinery capacity in Russia dipped, crude oil shipments hit a four-month high, as heavy domestic refinery maintenance left more crude available for export.

Russia exported on average 3.47 million bpd of crude in the four weeks to October 20, up by 140,000 bpd compared to the four-week average to October 13, Bloomberg data showed at the time.

That was a consequence of refining rates at Russian crude processing facilities dropping to their lowest level for more than two years, since May 2022.

Crude exports from Russia could soon rise again, as some refineries are struggling with losses amid the gasoline export ban, currently in place until December 31, 2024.

Russia’s refineries have reportedly started to reduce run rates and some are considering shutting in operations, as the facilities are struggling with hefty losses amid export restrictions, rising oil prices, sanctions, and Ukrainian drone attacks.