The army, led by Field Marshal Sheikh Khalifa bin Ahmed, took charge of ending protests that erupted last year, enforcing a period of martial law.
It was aided by Saudi and United Arab Emirates forces which Manama called in after accusing Iran of fomenting the protests.
“We have heard voices in recent days spreading hatred and abusing freedom of expression to the extent of insulting the Bahrain Defence Forces, and without doubt it is our duty not to allow this to be repeated,” the king said in a speech to senior military officers at their headquarters.
“The executive agencies must take the necessary legal measures to deter these violations,” he said in comments carried on the state news agency BNA.
Sheikh Ali Salman, leader of Wefaq, criticised the army at a rally on Tuesday, saying it would fail to suppress demands for democratic reforms.
“You wronged us, and you believe that what you did will stop us demanding our rights, but no matter what brute force you use, you will fail,” he said.
He also said that clerics have the ability to bring tens of thousands of Bahrainis onto the streets in protest.
Bahrain remains in a state of turmoil as Wefaq organises weekly mass rallies, and protesters in Shia villages and youths clash almost nightly with riot police.
Yesterday prosecutors also called in senior Wefaq official Sayed Hadi al-Mousawi for questioning and extended the detention for another week of prominent activist Nabeel Rajab over a tweet criticising Prime Minister Sheikh Khalifa bin Salman.
