BJP's prime ministerial candidate Narendra Modi's rallies, which are attracting large crowds, could be potential targets of anti-social elements and hence security is being enhanced at his rallies, an official told IANS. "Particularly after the bomb explosions at Gandhi Maidan in Patna where Narendra Modi was to address the rally, the contours of security for his rallies have certainly changed and we will ensure adequate security," a senior official said.