New Delhi, July 23 (IANS) The Delhi Metro Friday began trial runs on the much-awaited Central Secretariat-Lajpat Nagar section of the Badarpur corridor, an official said, adding that the line was expected to open by September. He said the trial runs on the nine-kilometer stretch would continue for a week. “The Badarpur corridor is expected to open for the public by September before the Commonwealth Games after attaining safety clearances,” said the official of the Delhi Metro Rail Corp (DMRC). After a week of trail runs, the Central Secretariat-Lajpat Nagar stretch would be gradually extended to Okhla and later to the other sections until Badarpur. “This line is one of the most challenging to construct for the DMRC as the total time available for construction was very short — only 41 months were available,” the official said. The 20.16 km Central Secretariat-Badarpur corridor was the second standard gauge corridor after the Inderlok-Mundka Metro line. There are 16 stations on the Central Secretariat-Badarpur corridor: Central Secretariat, Khan Market, Jawaharlal Nehru Stadium and Jangpura stations will be under ground while Lajpat Nagar, Moolchand, Kailash Colony, Nehru Place, Kalkaji Mandir, Govindpuri, Okhla, Jasola, Sarita Vihar, Mohan Estate, Tughlakabad and Badarpur stations will be elevated.