Indonesian police on Saturday expanded their search for 131 inmates, including four militants who escaped from an overcrowded jail during a riot that left five dead, a spokesman said. Inmates began rampaging through the jail in Medan city on Sumatra island on Thursday, setting fires and hurling bottles at guards in anger over power cuts and water shortages at the prison. The Tanjung Gusta jail was engulfed in towering flames, killing three inmates and two prison staff who were trapped in their office. "We stepped up efforts by instructing all police forces across Sumatra island to carry out a massive hunt operation," Heru Prakoso, spokesman for the North Sumatra police said. Security forces managed to regain control of the prison on Friday afternoon and had recaptured 81 of the 212 inmates who escaped, he said, adding that four convicted of terrorist offences were still on the loose.