The phrase "activists demonstrating" is correct and usable in written English.
It can be used to describe a group of activists who are participating in a demonstration or protest.
Example: "The activists demonstrating in the city center were advocating for climate change awareness."
Alternatives: "protesters rallying" or "demonstrators advocating".
It stared down city officials to hang on to its makeshift headquarters, showed its muscle Saturday with a big Times Square demonstration and found legions of activists demonstrating in solidarity across the country and around the world.
A mainstream secular newspaper ran an article about Ms. Benli and a group of activists demonstrating in a public area, saying they were subversives and religious radicals.
As proof of the supposed plot, the government and its lawyers cited videos and pictures of opposition party activists demonstrating and meeting "foreigners," including State Department officials and Senators Ted Cruz of Texas and John McCain of Arizona.
Turmoil and armed rebellions are so much a part of everyday life in Yemen that a few thousand students and opposition activists demonstrating at Sana'a University might not seem especially significant.
Many have clutched patriotic flags and wept this summer but most of them were fans of the England football team, distressed by its rapid exit from the World Cup, not activists demonstrating for and against the break-up of their country.
They were boycotted, received surly national publicity, and had activists demonstrating outside their stores.
Day after day, scores of activists demonstrated outside Brown's office.
Tens of thousands of activists demonstrated to exert pressure on negotiators, and rightly so.
Jamaat-e-Islam (JI) women activists demonstrated outside the party,s headquarters in Mansoora.
Activists demonstrated against iWright, a new software that can supposedly write novels and is supposedly backed by Google.
On Saturday morning, about 200 activists demonstrated outside the conference at the Ronald Reagan building, a couple of blocks south-east of the White House.
