Ultra-Orthodox men clashed with security guards in Beit Shemesh as tensions over a contested construction site boiled over on Monday.

Police said six people were lightly injured and six security guards and two managers at the Golobinzitz construction site were detained for investigation.

This was not the first violent incident to take place at the construction site, where a new Haredi neighborhood is set to be built over what protesters say is the location of Jewish graves.

Protests over the site began on August 12 as hundreds of ultra-Orthodox residents blocked entrances to Beit Shemesh and set fire to garbage cans and a forest area near the construction site, leading to 29 arrests. A smaller protest in Mea Shearim in Jerusalem saw a bus pelted with stones and garbage cans set aflame.

Two days later, a security guard was detained after throwing rocks at protesters. A border policeman was lightly injured and an ultra-Orthodox protester sustained a head injury during the resulting clashes. Three ultra-Orthodox men were arrested.

Also in August, Haredi businessman Aryeh Golobinzitz, one of the project’s managers, was beaten in his Jerusalem home by a number of men who identified as members of Atra Kadisha, a ultra-Orthodox group behind the protests who allege that the construction will disturb a complex of ancient Jewish burial caves.

The Atra Kadisha claims that there are approximately four hundred graves at the construction site, and opposes any further works.

The organization is joined by the sectarian Satmar Hasidic movement, which also called for a stop to all construction work at the site for fear of desecrating Jewish graves.