Danish ferry company DFDS Seaways said Sunday it has suspended its services linking northern France's Calais and England's Dover after one of its vessels was hit by a distress signal.
"On Saturday night, one of our ferries, the Malo Seaways, was the target of distress flares, one of which struck our ferry," a company spokesman told AFP.
"After these incidents and due to safety concerns for our staff, our ships and our passengers, we have decided to suspend our service to Calais until further notice," he added.
On its Twitter account, the company said the suspension will last "until Tuesday 28 July due to continued disruption".
The company runs 10 crossings a day each way between Dover and Calais.
Traffic has been diverted to Dunkirk in northern France from Calais.
The Danish company's services have been disrupted in recent weeks because of industrial action by workers of a French company MyFerryLink.