NEW DELHI (AP) — Kingfisher Airlines canceled scores of flights across India on Monday after pilots refused to work in protest at unpaid salaries.

At least 40 flights across India were canceled after the airline’s pilots called in sick.

Thirteen flights from India’s financial capital, Mumbai, and three flights from New Delhi were among the 40 canceled.

Kingfisher has blamed the tax department for its woes. The airline said in a statement that delays in paying salaries happened because the company’s bank accounts had been frozen by tax authorities.

It also said the frozen bank accounts were the reason for its suspension last week from the International Air Transport Association’s payment clearinghouse.

The IATA system allows airlines to divide the money from codeshare flights or multi-leg journeys involving several carriers. Kingfisher was suspended from the IATA on Wednesday because of unpaid bills.

Kingfisher has been struggling with a debt of $1.3 billion. In the past few months the airline has grounded planes, failed to pay staff and canceled flights. It has been in the red since beginning operations in 2005.

The airline was making efforts to remedy what it called a "temporary situation," the statement said. It said it is operating 80 percent of its scheduled flights and expects to return to a full schedule soon.

Passengers whose flights were canceled were either being accommodated on other airlines or offered a full refund, the airline said.