(JTA) — Israeli security officials said Palestinian Authority President Mahmoud Abbas is working to calm tensions in the West Bank, even as violence has surged.

An unnamed security official said Friday that “lone wolf terrorism,” attacks by individuals acting on their own, is the main cause of the current violence, the Times of Israel reported, citing Israel Radio.

Meanwhile, Palestinian leaders in Gaza have called on Palestinians in the West Bank to escalate violence, with a member of the political wing of the Gaza-based Islamic Jihad urging the PA’s security forces to halt all cooperation with Israel and to confront IDF troops and settlers.

In addition, Hamas leader Ismail Haniyeh, at weekly Muslim prayers in Gaza City Friday, called for “the strengthening and increasing of the intifada…”

Soon after Haniyeh’s speech six Palestinians were killed and 19 others hurt by IDF soldiers in a protest on the Gaza-Israel border.

Defense Minister Moshe Ya’alon said Friday that Hamas was responsible for the fatalities, because it had encouraged the protesters to approach the border fence, from where they rolled burning tires and threw stones at Israeli soldiers on the other side.