Forces from the GCC Peninsula Shield will remain in Bahrain after a state of emergency is lifted next month, the head of Bahrain's military said, as the Gulf state continues to clamp down on protests.

Gulf forces would remain in Bahrain "in anticipation of any foreign threat", commander-in-chief Sheikh Khalifa bin Ahmed al-Khalifa was reported as saying by the state news agency BNA.

He warned protesters against returning to the streets. "I say to those who did not get the message, if you return we will come back stronger this time."

US-allied Bahrain, headquarters of the US Fifth Fleet, is set on June 1 to lift martial law imposed in March after weeks of anti-government protests.