The leader of Yemen's powerful Huthi rebels on Thursday threatened retaliation over a land, air and sea blockade imposed on the war-torn country by a Saudi-led alliance supporting the government. 

"We warn the forces of aggression against prolonging the blockade," imposed after a November 4 Huthi missile attack targeting Riyadh, rebel chief Abdulmalik al-Huthi said in a televised speech. 

"Should the blockade continue, we know what (targets) would cause great pain and how to reach them," he said, in an implicit warning of fresh missile attacks.