Washington: Republican Party's presidential candidate Donald Trump said that his Democratic rival, Hillary Clinton, should be imprisoned for her misuse of email when she was the Secretary of State. "I will say this: Hillary Clinton has got to go to jail. Honestly, she's guilty as hell," Trump told his supporters at a rally in San Jose, California, on Thursday where violence erupted as his supporters clashed with protesters. The business mogul had earlier accused Clinton of violating federal law by using her personal email account for official business when she was the head of US diplomacy, the position she held from 2009 to early 2013. Clinton, on the other hand, accused Trump at a rally in San Diego, California, that he lacks the temperament and preparation required to be President. "Donald Trump's ideas aren't just different - they are dangerously incoherent" said former Secretary of State, adding "it's not hard to imagine Donald Trump leading us into a war just because somebody got under his very thin skin." Clinton is criticised by many Republicans saying that her email misuse could have jeopardised US national security. The FBI is investigating her use of an private and unsecured email server during that time.