Prime Minister Syed Yousuf Raza Gilani has said the troops have been called back from Kohlu in Balochistan and replaced by the Frontier Constabulary. Addressing a joint session of the parliament here Wednesday, Gilani said the government has determined to explore the causes of the killing of veteran Baloch leader Nawab Akbar Khan Bugti. The Prime Minister said that the government was ready to engage all exile leaders of Balochistan in dialogue.