Metro Railway services were today affected in the southern part of Kolkata during morning rush hours from 9.05 am owing to a technical snag in a rake. Train services from Kavi Subhash station in the far south to Mahanayak Uttam Kumar station were stalled for 20 minutes after a brake-binding snag in a rake at Shahid Khudiram station, Metro spokesperson Indrani Banerjee said.