Seoul subway Line No. 2 was delayed over 20 minutes during morning rush hour due to a conductor taking an urgent toilet break on Monday, according to Seoul Metro.

The conductor who was driving a train on the outer lane of the circular route had to leave the train urgently to use the toilet in a station at 8:11 a.m.

While an engineer watched the train, the conductor ran down the platform and returned in 4 minutes 16 seconds after using the restroom on another floor.

However, the 125 trains following it had to be rescheduled and many of them were delayed 20 minutes from their originally scheduled arrival times, Seoul Metro said.

But, it added there might not have been any major inconvenience to passengers, as the trains continued to arrive and depart at the same intervals as usual.

Conductors driving the circular lanes are required to work for 2-3 hours straight without any breaks. They can use portable toilets in an emergency, but in some cases, they have no other choice but to use restrooms in stations distant from the platform.