From YNet:
Six foreign nationals and Palestinians set fires alight near the West Bank settlement of Bat Ayin in the Gush Etzion bloc. Police said the suspects were taken in for questioning on suspicion of arson and illegal congregation.
Settlers said that at about 11 am they saw fires on lands they said belonged to Bat Ayin. Security sources said it was apparently land whose ownership is not regulated.
Dov Mark, land supervisor for the Gush Etzion Council, said such acts have taken place a number of times. "This is a known Palestinian method to take over state land," he said. "With the support of anarchists, who usually come from abroad, they come to an area of natural woodland which has never been cultivated, burn it on purpose and at the same time plant trees. It's all supposed to alter the reality on the ground."
Mark warned that "in this way, it's hard for the Israel Land Administration to work from the moment they plant trees on the land or cultivate it for agricultural crops. In today's case, some 80 dunams (20 acres) of natural woodland were burned by a group of 25 Palestinians and anarchists."
I grabbed the YNet video and put it on YouTube:
(h/t Jed)