Omg, foreign Aryan missionaries thats some leftist bull crap,Outright evidence of Hindu persecution of Buddhists is hard to come by, because Indians didn't write history. Even evidence for the Muslim persecution of Hindus and the Portuguese Inquisition in Goa come from Muslim and Portuguese sources respectively. There is hardly anything from the Hindu side. So historians use conjecture to infer Hindu persecution of Buddhists based on indirect evidence, and the ambiance of the times.
For example, Historian Sreedhara Menon writes in book 'A survey of Kerala History', about the time of 8th - 9th centuries when Kerala was Hinduised by foreign Aryan missionaries:
"The new Aryan missionaries devoted all their attention to propaganda against Buddhism and Jainism whose hold on the people was the main stumbling block to the success of their ideology and before long these religions lost their following among the people. It is also possible that the Aryan missionaries resorted to a deliberate policy of destroying Buddhist Viharas and images. The broken and damaged Buddhist images obtained from places such as Karumadi and Pallikal, perhaps, bear testimony to this. ----" (p.105).