Welcoming return of Kerala nurses from Iraq, Congress leader Amarinder Singh Saturday urged the Centre to intensify its efforts for freeing 39 Indians being held hostage in the strife-torn nation."While it was a matter of great satisfaction and immense relief that the nurses had returned home, there was an overwhelming concern and anxiety among the relatives of captured youth, most of whom are from Punjab, Haryana and Himachal Pradesh," the former Punjab chief minister said."It is now more than two weeks since the youths had contacted their relatives (in India). Since then there is no word from them as under what conditions they have been kept and how and when they will be released," he said."The government must intensifying its efforts for their release."According to India's external affairs ministry, 39 Indian nationals continue to be held captive by militants in Mosul.