Vibhasa, another 2nd century text, states that Pushyamitra burned Buddhist scriptures, killed Buddhist monks, and destroyed 500 monasteries in and ar… - Pushyamitra Shunga

The climax was reached when the same Marxist professors started explaining away Islamic iconoclasm in terms of what they described as Hindu destruction of Buddhist and Jain places of worship. They have never been able to cite more than half-a-dozen cases of doubtful veracity. A few passages in Sanskrit literature coupled with speculations about some archaeological sites have sufficed for floating the story, sold ad nauseam in the popular press, that Hindus destroyed Buddhist and Jain temples on a large scale. Half-a-dozen have become thousands and then hundreds of thousands in the frenzied imagination suffering from a deep-seated anti-Hindu animus. ... And these “facts” have been presented with a large dose of suppressio veri suggestio falsi.... A very late Buddhist book from Sri Lanka accuses Pushyamitra Sunga, a second century B.C. king, of offering prizes to those who brought to him heads of Buddhist monks. This single reference has sufficed for presenting Pushyamitra as the harbinger of a “Brahmanical reaction” which “culminated in the age of the Guptas.” The fact that the famous Buddhist stupas and monasteries at Bharhut and Sanchi were built and thrived under the very nose of Pushyamitra is never mentioned. Nor is the fact that the Gupta kings and queens built and endowed many Buddhist monasteries at Bodh Gaya, Nalanda and Sarnath among many other places. (...)

Hsuan Tsang is notorious for his exaggerations and his insertions of miracle stories, and he had to explain to China, where Buddhism was readhing its peak, why it was declining in India. It seems safer to base our judgement on the fact that in his description of Buddhist life in the Ganga basin, nothing shows the effects of recent persecutions. In fact, Hsuan Tsang himself gives a clue to the real reason of pre-Islamic Buddhist decline, by describing how many Buddhist monasteries had fallen into disuse, esp. in areas of lawlessness and weak government, indicating that the strength of Buddhism was in direct proportion to state protection and patronage. Unlike Brahminism, which could sustain itself against heavy odds, the fortunates of Buddhist monasticism (even more than those of the Christian abbeys in early medieval Europe) were dependent upon royal favours, as under Ashoka, the Chinese early T'ang dynasty, and the rulers of Tibet and several Southeast-Asian countries.

The oft-repeated allegation that Pushyamitra Sunga offered a reward for the heads of Buddhist monks is a miraculous fable related exclusively in a hostile source and contradicted by the finding of art historians that Pushyamitra was a generous patron of Buddhist institutions.