POLICE are investigating after youths were seen throwing lit fireworks into the potash drilling compound near Hawkser.
The four youths approached from the disused railway line, before throwing the lit fireworks onto the site.
The preliminary rig has been set up by York Potash to explore the levels of potash in the area.
Police said workmen had recently hit gas pockets during their operations making lit fireworks even more dangerous on-site than they usually would be.
This is one of several incidents which have occurred around the compound, including one instance of vandalism, in which a high voltage cable was ripped off a generator, and another of unknown individuals throwing a lit firework out of a white transit minibus.
Gareth Edmunds from York Potash said: “Our temporary drilling sites have a 24 hour security team in place and they were able to contact police immediately.
“We’d like to thank the police for their response and we’ll continue to assist them with their enquiries.
“The safety of our people and our work is of the upmost importance and fortunately no one was hurt and our drilling was unaffected during this incident.”