A senior Turkish general called for calm on Wednesday after two prominent retired generals were detained in a widening police investigation into a suspected coup plot against the government. “Turkey is passing through difficult days. We all have to be acting with more common sense, more carefully and more responsibly,” land forces commander General Ilker Basbug, who is the second most powerful official in the Turkish military, told reporters. Police detained 21 people on Tuesday as part of a nationwide investigation into Ergenekon, a shadowy, ultra-nationalist and hardline secularist group suspected of planning bombings and assassinations calculated to trigger a military takeover. The detentions of retired first army chief General Hursit Tolon and retired gendarmerie forces General Sener Eruygur inside military residences have sent shockwaves through Turkey, and newspapers said such moves were unheard of.