Libya has turned away the Proteus Philippa oil tanker that was due to load a cargo from one of its ports, after the vessel previously performed a voyage to Israel.

The vessel was set to load 600,000 barrels but was asked to leave because it transported barrels to Haifa in Israel.

Mellitah Oil & Gas Co., which operates the terminal, didn’t allow the tanker to enter port and load after confirming that it had previously been to Israel’s Haifa Port and asked it to leave, a company official told Bloomberg. Two other people with knowledge of the matter confirmed the information.

Port authorities in Libya have recently stepped up checks on tankers’ prior voyages in light of the war in Gaza, which has caused anger toward Israel to grow across the Arab world.

Three shipbrokers and one owner told Bloomberg that it’s common practice for tankers that go to Israeli ports to switch off transponders that tell satellite monitoring systems where they are and where they’re headed. 

That’s because most Arab countries don’t recognize Israel and can reject vessels that went there previously. 

Porteus Phillippa loaded crude from Gabon Sept. 8-10 and signaled Haifa on Sept. 25 when it reached the Mediterranean. The tanker switched off transponder Oct. 1. when it approached Israel. On Oct. 6 the transponder was back again with draft dropped to 8.5 meters from previous 14 meters, suggesting the cargo has been discharged.