The Israel Defense Forces said on Sunday that troops had arrested 13 wanted Palestinians overnight as tension remained high in the West Bank.

All were wanted for “illegal activities,” a military spokeswoman said, indicating they were picked up in the southern cities of Hebron and Bethlehem, as well as in two villages north of Ramallah.

She did not specify exactly why they were wanted.

Troops went on high alert on Thursday after two youths were shot dead by Border Police during a demonstration near Ramallah to mark the anniversary of the Nakba, or “catastrophe,” that befell Palestinians when Israel was established in 1948.

Their deaths sparked further angry clashes, and several thousand people attended their funerals on Friday.