Several MDC-T MPs and senators are awaiting trial on similar charges and party spokesman, Nelson Chamisa said they feared a new wave of political persecution.
Job Sikhala who recently formed his own MDC-99 has also been hauled before the courts for allegedly insulting Mugabe.
Chamisa said Jembere was arrested alongside MDC provincial treasurer Gilbert Kagodora at a rally at Wadzanai Shopping Centre in Shamva, Mashonaland Central.
“They were arrested around 2pm and we understand the police are saying they insulted Mugabe when they chanted one of our slogans,” Chamisa said.“They were attending one of our real change rallies and we had notified the police about the rally.”
The arrest of the two came a day after police detained Marondera Central MP Ian Kay on charges that he kept expired drugs and arms of war at his Helensvale house.
“They searched the house and garage, ostensibly for drugs and unlicensed firearms,” Chamisa said.
The six police officers said they had reasonable grounds to believe that Kay was in possession of dagga, cocaine, heroin, hashish, ecstasy, pornographic material, smuggled goods, unlicensed firearms, unregistered and expired drugs.
“Although nothing was found in the house, Kay was arrested and taken to Harare Central police station where he is still detained,” he said.
Chamisa said the MDC-T will approach the co-Home Affairs ministers Giles Mutsekwa and Kembo Mohadi to register their displeasure at the conduct of the police.
Police spokesman, Andrew Phiri said he needed time to get information about the arrests before issuing a comment.
But subsequent attempts to contact him on his mobile phone was unsuccessful as it continuously went on voice mail.