The Associated Press

TEHRAN, Iran — Iran’s seizure of a British oil tanker was a response to Britain’s role in impounding an Iranian supertanker first, senior officials said Saturday, as newly released video of the incident showed Iranian commandos in black ski masks and fatigues rappelling from a helicopter onto the vessel in the strategic Strait of Hormuz.

The spokesman for Iran’s Guardian Council, Abbas Ali Kadkhodaei, was quoted in the semi-official Fars news agency describing the seizure as a legal “reciprocal action.”

The seizure prompted condemnation from European countries as they continue to call for a de-escalation of tensions in the critical waterway.

U.K. Foreign Secretary Jeremy Hunt said Britain’s response “will be considered but robust.” In comments on Twitter on Saturday, he said he spoke with Iran’s foreign minister and expressed extreme disappointment that the Iranian diplomat had assured him Iran wanted to de-escalate the situation but “they have behaved in the opposite way.”

Speaking to reporters later Saturday after an emergency government meeting, Hunt said the “totally and utterly unacceptable” interception of the British-flagged Stena Impero “raises very serious questions about the security of British shipping and indeed international shipping” in the Strait of Hormuz.

The free flow of traffic through the Strait of Hormuz is of international importance because one-fifth of all global crude exports passes through it from Mideast exporters to countries around the world.

23681080