Tens of thousands of travellers faced flight delays and cancellations Friday as workers at eight airports in Germany went on strike to demand better pay.

The full-day walkout, called by the Verdi trade union, prompted Germany's biggest carrier Lufthansa to cancel more than 1,300 flights at its two busiest hubs, Frankfurt and Munich.

"The strike is expected to have a strong impact, especially on domestic air traffic, ranging from delays to cancellations and even a partial shutdown of air traffic," Verdi said in a statement.

German airport association ADV called the strike action "completely unacceptable", saying it would affect around 295,000 passengers and more than 2,300 flights all together.

"Solutions must be found at the negotiating table and not at the expense of passengers," ADV chief Ralph Beisel said in a statement.

The other affected airports are in the cities of Bremen, Dortmund, Hamburg, Hanover, Leipzig and Stuttgart.

Verdi is currently leading negotiations for public sector workers, airport ground crew and aviation security staff, demanding better pay at a time when workers are seeing their incomes eroded by the higher cost of living.

Verdi has defended the walkout, saying a combined day of action was less inconvenient for passengers than several strikes on different days.

The next round of talks with employers is scheduled for February 22-23.

Frankfurt and Hamburg airport urged passengers not to come to the airport at all. Those travelling within Germany were advised to switch to train journeys.

Munich airport scrapped all its regular passenger flights.

Verdi said the nationwide strike would not impact flights delivering aid to earthquake-hit Syria and Turkey, or planes carrying leaders attending the annual Munich Security Conference.

The strike caps a chaotic week for air travel in Germany.

Lufthansa was forced to cancel or delay flights on Wednesday because of a major IT outage caused by construction work in Frankfurt.

The next day, several German airports saw their websites disrupted by a suspected cyber attack.

German news outlet Der Spiegel said a group of Russian hackers had claimed responsibility for the attack.