TEHRAN, Iran (AP) — Iran should consider seizing a British oil tanker in response to authorities detaining an Iranian oil tanker off the coast of Gibraltar, a former leader of the Islamic Republic's powerful Revolutionary Guard said Friday.

The striking comment by Mohsen Rezaei came amid heightened tensions over Iran's unraveling 2015 nuclear deal with world powers, an accord that the U.S. withdrew from last year.

In recent days, Iran has broken through the limit the nuclear deal imposed on its stockpile of low-enriched uranium and plans on Sunday to boost its enrichment. In the past months, t...