Workers in Rotterdam, Europe's largest port, went on strike Thursday for the first time in 13 years, fighting to keep hundreds of jobs they say may be lost to automatisation.
"The union is demanding assurances that there will be no forced job cuts as a result of the implementation of new highly-automated terminals," the two unions, the FNV and the CNV, said in a statement.
The 24-hour strike began at 1415 GMT, the daily Financieel Dagblad said, adding however that some of the terminals were still at work later in the day.
According to the financial daily, workers last downed tools at the port some 13 years ago.
The Dutch news agency ANP said 700 workers -- out of a total workforce of around 3,600 -- had joined the strike.
Port authorities did not respond immediately to a request from AFP to comment on the situation.
The unions claim some 800 jobs are under threat following the opening of new terminals at an extension to the Rotterdam port known as Maasvlakte.
The biggest maritime project in several decades in the Netherlands, Maasvlakte has doubled the port's capacity for handling containers.
Some 450 million tonnes of freight and cargo passes through Rotterdam each year, carried on some 30,000 seagoing vessels and 110,000 inland vessels which visit the port annually.
The unions are urging that no one be forced to leave their jobs before 2020 and that conditions for older workers improved.
Strikes are rare in the Netherlands which has a strong tradition of social dialogue. According to the European observatory of industrial relations (EIRO), there were between five to seven strike days in Holland between 2005-2009, compared with 132 in France over the same period.