A government official says Japan has temporarily suspended the annual Antarctic whaling after repeated disruptions by a conservationist group.

The Sea Shepherd Conservation Society has been chasing the Japanese whaling fleet for weeks in the icy seas off Antarctica, trying to block Japan’s annual whale hunts, planned for up to 945 whales.

Fisheries agency official Tatsuya Nakaoku says Japan has halted the hunt since February 10 after persistent disruptions by the anti—whaling protesters “to ensure safety.”

He said the fleet plans to resume hunting when conditions are deemed safe.

The annual whale hunts for scientific purposes are allowed by the International Whaling Commission as an exception to the 1986 ban, but opponents say they are a cover for commercial whaling.