Guwahati: Two youths were detained by Dispur Police for allegedly painting a portrait of environmentalist Sonam Wangchuk on a flyover pillar without official permission. They were later released after the police issued a warning.Both the students were from the Government College of Art and Crafts.Deputy Commissioner of Police (East) Hiranya Kumar said the duo was caught while allegedly painting on a government structure during a routine night patrol.Also Read: Wangchuk calls July 20 march 'India's second freedom movement' in message from hospital detention"During night patrolling on Friday near Tribeni Path, towards the Jyoti Bishnu Auditorium, a police team found two youths painting on a government wall using different colours. They were immediately apprehended, and a case was registered at Dispur Police Station," he said.He added that the two students would be released after being warned against painting or altering public property without prior permission from the authorities.Kumar said the students told the police they were not associated with any political party or organisation and claimed they had painted the portrait independently.The Assam government recently directed that murals, graffiti, paintings or writings on flyovers, bridges and other public structures be prohibited without prior approval.Also Read: 'Lost faith in Safdarjung Hospital': Wangchuk's wife moves HC over transfer pleaWangchuk has recently been on a 20-day hunger strike demanding Education Minister Dharmendra Pradhan's resignation over the NEET paper leak.