At least four people were injured in an explosion in the Gandawa area of Jhal Magsi district of Balochistan, officials said.They said that a convoy of supporters of former Balochistan MP Sardar Yar Mohammad Rind was on way from Shoran to Gandawa when at the Beeburg wah area roadside bomb exploded, Associated Press of Pakistan reported.As a result, four persons sustained injuries, who were rushed to GandawaHospital.