Volunteers have picked up almost 15,000 kilos of rubbish from Dutch beaches in the past two weeks, foundation De Noordzee said on Wednesday.

In total, 2,748 people combed the North Sea coast from Cadzand in the south to the Wadden Sea island of Schiermonnikoog. Most of the waste collected was made up of plastic – including empty drinks bottles, tops and balloons. But volunteers also found a mattress, a pregnancy test and an armed forces dummy bomb.

This year for the first time volunteers cleaning a piece of beach by Scheveningen were asked to pick up as many cigarette ends as they could in 20 minutes. They found a total of 3,733.

Cigarette filters are made up of tiny pieces of plastic which enter the marine environment when butts are left on the beach.

‘The results of our waste investigation, which we have been carrying out since 2004, show that there are an average of 375 items of waste on every 100 metres of beach,’ foundation director Floris van Hest said.