Afghan police have arrested 30 suspects in the wake of yesterday's bloody protest in Mazar-e-Sharif city, capital of northern Balkh province that left seven United Nations workers dead. An Interior Ministry spokesman Zamari Bashari today said as many as 30 suspects have been detained by police and an investigation is underway to find the fact how the demonstration turned to violence and who were behind murdering seven foreign staff of the world body. He said those killed in the incident include four UN security guards and three UN civilian employees while another UN civilian staff was injured. According to Bashari, four demonstrators were also killed in the clash while a total of 23 others injured in the violent incident. He said the Interior Ministry today sent a high- ranking delegation led by head of Counter-terrorism Department of the Ministry General Nazim Mohammad Yarman to investigate the incident.