BANGKOK (AP) — Thailand’s anti-graft commission on Thursday summoned the embattled prime minister to hear charges of negligence for allegedly mishandling a government subsidy program, as her supporters blocked access and chain-locked one of the gates to the agency’s headquarters in Bangkok’s outskirts.

The charges from the National Anti-Corruption Commission could lead to Prime Minister Yingluck Shinawatra’s impeachment after three months of street protests by her opponents and mounting violence that has prompted fresh concerns from the U.S. and the U.N.