Berlin-based Germania airline has stopped all flights and applied for bankruptcy after failing to cover a “short-term liquidity problem.” The carrier had been transporting over four million passengers a year.

Germania had “no other option” but to file for bankruptcy following financial trouble, the airline’s CEO Karsten Balke said on Tuesday.

The Berlin-based company cancelled all flights and advised passengers to contact their travel agents about alternative arrangements.

People who bought their tickets directly from the company “unfortunately have no claim to alternative trips,” the company said.

Balke blamed “unforeseen circumstances” for the bankruptcy, such as the rise in kerosene prices, the devaluation of the euro against the dollar, and unexpectedly high maintenance costs.

“Unfortunately we were ultimately unable to successfully conclude our financing efforts to cover a short-term liquidity problem,” he said.

Balke apologized to passengers and praised employees for their quality work, “even in the tense weeks we’ve just had.”

The mid-market airline ran flights to around 60 destinations in Europe, Africa, and the Middle East, transporting more than four million passengers per year.

After boasting of a monetary windfall of over €15 million ($17.16 million) in January, the company said last week that their staff had not received their salaries for the entire month of January.

Germania’s bankruptcy filing comes more than a year after Air Berlin became insolvent and its ceased operations.