The ferry service from Sliema to Valletta the government was operating to mitigate the effects of the public transport strike was suspended following threats to members of the crew who are refusing to work even under police escort.

A number of passengers were stranded in both Sliema and Valletta yesterday.

The incident occurred only a few hours after a second ferry with a capacity of 260 passengers was added to the service.

Trouble flared when an attempt by striking bus drivers to go to Sliema by ferry from Marsamxett in Valletta was foiled when drivers disembarked and were not allowed on again.

The 30 or so drivers said they just wanted to go to Sliema for a coffee and had as much right as anyone else to use the ferry.

The drivers said they boarded at about noon when there were about a dozen tourists on board. When the captain realised that there were bus drivers, he asked the tourists to get down as another ferry would pick them up.

The drivers said they disembarked together with the tourists and although it was true that another ferry could be seen arriving, it turned back when it was mid way.

In the meantime, more tourists arrived, waiting for the boat. By then, a big contingent of policemen, led by Superintendent Neil Harrison, was on site.

The drivers argued with the police that they were there first, so they should be allowed to board the ferry first. A police line was formed and the drivers were blocked from boarding the ferry.

The drivers kept arguing they were being treated as second-class citizens, that they were not criminals and that it was the police who were making them out to be criminals.

Drivers said later they had even asked the policemen on duty to join them for a coffee in Sliema.

Mr Harrison tried to tell them that another ferry would be calling for them soon but they said they wanted to go to Sliema on the boat that was leaving because they had the right to board the ferry before many others who did.

"We came here quietly... You want us to cause trouble. Next time that's what we'll do. After all, we have now lost everything. It makes no difference if we die now or in a month's time," one argued.

The drivers then walked back to the city centre.

The master of the ferry operating between Valletta and Sliema was threatened when the ferry berthed in Sliema.