New Delhi: Delhi Police arrested former Jawaharlal Nehru University (JNU) student Umar Khalid under the Unlawful Activities (Prevention) Act in connection with northeast Delhi riots that broke out in February this year.Khalid has already been booked under the Unlawful Activities (Prevention) Act (UAPA) along with Jamia student and RJD youth wing president Meeran Haider, JCC media coordinator Safoora Zargar, and Danish, a resident of northeast Delhi’s Bhajanpura.“My son Umar Khalid has been arrested tonight at 11 p.m. by Special Cell, Delhi Police under UAPA. Police was questioning him since 1 p.m. He has been implicated in Delhi riots,” said Syed Qasim Rasool Ilyas, father of Umar Khalid.Khalid was summoned on Saturday and Sunday. He was arrested after being questioned for around 10 hours and will be produced before a Delhi court on Monday.Earlier on September 2, Khalid was called by the Crime Branch for questioning in the northeast Delhi riots case. He was let off after the questioning.The arrest comes hours after Delhi police issued a statement on Sunday in which it has asked those who have doubts and questions about the northeast Delhi riots probe to take legal course at the appropriate time.The Delhi police said that various interest groups are using social media platforms and other online portals to raise questions about the fairness of investigation of the northeast Delhi riot cases.Earlier, retired IPS officer Julio Ribeiro, who was former Mumbai police commissioner, DGP Gujarat and Punjab, and former Indian Ambassador to Romania, has written to Delhi Police Commissioner S N Shrivastava, questioning the probe into the northeast Delhi riots cases.Since December, Delhi was brimming with tensions after the Citizenship Amendment Act (CAA) was passed. A sit-in protest against it started at various parts of the national capital. An agitation also started near Jafrabad metro station in northeast Delhi.The protests in northeast Delhi turned violent and around 53 people were killed.