State-run, Air India has announced its decision to sack a group of 10 pilots on Tuesday after they went on a agitation against the airline.

The airline management also announced that it is derecognizing their union. It also moved to seal its office after 160 failed to join duty, which resulted in the cancellation of five international flights since previous night.

Civil Aviation Minister Ajit Singh described the mass sick leave as illegal and the airline has hinted that more severe action will be taken if the pilots do not go back to work by 6 pm on Tuesday.

"They are reporting sick. They have not given any notice for any strike. So whatever the Air India management rules and regulations, action will be taken accordingly," Singh said.

An Air India spokesperson said that flights on Delhi-Toronto, Delhi-Chicago, Mumbai-Newark and Mumbai-Hongkong via Delhi sectors were cancelled as the pilots did not come for work. In an unprecedented move, the management has started sending doctors to the homes of pilots after they called in sick.

Among the ten pilots who have been sacked by the airline, some are office bearers of the Indian Pilots Guild (IPG), which is heading the protest against the management. The management derecognized the IPG and sealed its offices in Delhi and Mumbai.