More than 50 suspect persons have been arrested in connection with a suicide blast at rescue 15 building in Lahore on Wednesday. An investigation team comprised of two additional IGs and a DIG and other police and sensitive agencies officials probing the blast. No major clue has been found so far despite passing 24 hours. Meanwhile, 50 suspects have been arrested for investigations during raids in Afghan settlements. Security also beefed up at entry and exit routes of the city.