Two tankers carrying Russian flagship Urals crude have been idling off the West Coast of India for more than three weeks without any indication of when they will unload.

The Aframax tanker Crude Centurion arrived at the West Coast of India on Feb. 21, about 100 miles away from Sikka, its destination. Another, the Afragold, had been floating nearby since Feb. 29 after briefly signaling Mundra. Both loaded about 700,000 barrels of Urals from Russian Baltic sea port Primorsk in January. 

It remains unclear why they have been idling but there are growing signs that western sanctions are disrupting the fleet of tankers moving Russian oil. 

Tankers transporting the nation’s barrels have been doing strange things following a ramp up in US sanctions targeting traders and shipping companies moving the nation’s petroleum. Over the past few months, several tankers idled in the Indian Ocean for days before discharging in Indian ports or diverting to Middle East. 

Russia’s Sokol crude was hit hardest by tightened sanctions. At its height, the stranded oil amounted to as much as 18 million barrels earlier this year after Indian refiners shunned the grade. The backlog is finally clearing up with most tanker heading to China after idling weeks in water. 

Shipments of Urals have been relatively undisturbed.

Afragold is managed by a firm called Universal Tanker Mgmt UTM-MAI, according to the Equasis international maritime database. A Malta phone number listed for the company didn’t work. Crude Centurion is managed by Athens-based Stealth Maritime Corp. A person answering the phone said nobody was available to comment because it’s a public holiday in Greece.