COTABATO CITY, Maguindanao: Police were placed on heightened alert in and around Koronadal City after farmer-protesters demanding rice subsidy from the government occupied portions of the national highway connecting Koronadal and General Santos City.

The protesters have barricaded the four-lane highway by sitting down and lying on the concrete highway since Sunday, causing inconvenience to commuters who were forced to detour via the town of Tampakan.