A strike by Finland's aircraft mechanics, which began on Monday, has grounded about 20 flights and will cause more flight cancellations if it continues.

About 900 mechanics belonging to the Finnish Aviation Union launched the open-ended strike at 5 a.m. local time (0300 GMT) Monday after talks between union representatives and management broke down on wages and working hours.

Flag carrier Finnair said it had canceled 18 flights, most of which were domestic services with four international flights heading for Stockholm and Geneva.

Budget airlines Finncomm and Blue 1 also said the strike was causing minor disruption.

It is estimated that the three airlines would be forced to cancel up to half of their flights if the strike continues on Tuesday, and to ground all flights if it continues on Wednesday.

Late Sunday, the Finnish Aviation Union and the Association of Support Service Industries rejected a settlement proposal presented by national labor arbitrator Esa Lonka.

It was unknown when the negotiation was to resume.