The protesters have been holding demonstrations and blocking roads in Kent County for more than a week.
RCMP Cpl. Chantal Farrah said a small number of people tried to block work crews in the area.
"They were attempting to block the heavy equipment from travelling on the road. Now the people who were doing so were breaking the law and they were informed that they were breaking the law and that they needed to move," Farrah said.
"They refused and 12 people were arrested, so of those people there were seven men and five women."
The road has since been cleared and Farrah says there have been no further incidents.
As of Thursday, Public Safety Minister Robert Trevors said there had been nine arrests associated with the anti-shale gas protests in the area.
SWN Resources Canada is conducting seismic testing in Kent County.