Anonymous threat
A file photo of Killer whales chasing a school of dolphins in the ocean, off Nagasaki Prefecture - (Reuters) Reuters

Hacktivist group Anonymous has issued a threat against the Japanese government over its controversial dolphin and whale hunting programmes.

Anonymous Operations has sent a warning message to the Japanese government over the slaughter of dolphins in Taiji, Wakayama Prefecture.

"Government of Japan, we have been watching you and your sick actions from a very long time. Despite several pleas from the international community, you have not stopped butchering these mammals, for your personal gains. You are putting your people's lives at risk by allowing them to consume whale meat. Not only that, you have brought great shame upon Japan by performing these acts.

"This is our final warning, STOP these slaughters IMMEDIATELY, or get ready to face the extent of our wrath."

The group has listed nearly two dozen websites, including those of the prime minister's office and several other ministries, for the targeted attack, dubbed "OpKillingBay".

Japanese officials are said to be on high alert over the warning.

Although the hackers claimed some of the sites have already been taken down, they appeared to be working at the time of writing.

It is not yet clear whether the original hacktivist group Anonymous is leading the attack. The AnonNews Twitter account has not put out any word on the threatened attack.

The annual slaughter of dolphins in Taiji was first brought to the world's attention in the award-winning 2009 documentary The Cove. Local fishermen claim that the cull is necessary to protect fish stocks.

Watch the trailer for The Cove below: