New Delhi: Madhya Pradesh has tightened security across the state ahead of the visit by Sri Lankan President Mahinda Rajapaksa who will be inaugurating a Buddist University in Sanchi. The MDMK of Tamil Nadu had announced a protest in the state against his visit. MDMK General Secretary Vaiko had called for a black flag demonstration against the Sri Lankan President for the alleged violation of rights of the ethnic Tamilians in the country during its war against the Liberation Tigers of Tamil Eelam (LTTE). Vaiko, who left Chennai for Sanchi on earlier this week, was, however, stopped from entering the state.