COPENHAGEN, Denmark (AP) — Sympathy strikes across Finland’s transport sector have brought Helsinki to a virtual standstill and prompted flag carrier Finnair to cancel almost 300 flights.

Buses and ferries in the Finnish capital were also being affected by the strikes, which are aimed at showing support to some 10,000 postal workers.

Finnair said Monday its flight cancellations will impact at least 20,000 customers and that the strike will affect “several critical services” at Helsinki’s airport — a hub for Europe-Asia connections.

Postal workers have been on a two-week strike over pay. Talks to reach an agreement failed late Sunday.

It was not immediately clear how long the strikes would last.