The Red Line runs from Dilshad Garden to Rithala.
This could have led to the delay in train services for some time, Delhi Metro Rail Corporation (DMRC) officials said.
Due to some signalling (inter-locking) issue at Pitampura, the trains were manually controlled between Keshavpuram and Rohini West section from 9.30 to 10.15 am, they said in a statement.
The glitch might have led to "little bunching or delay during the period on the section", it said, adding that the services on the rest of the line was normal.