Four Palestinian youths were wounded in clashes early Monday with Israeli forces who were demolishing the West Bank homes of two assailants' families, a Palestinian health official said. One of the four was seriously wounded, Ramallah hospital director Ahmad Bitawi said. The Israeli military said troops were in the Qalandiya refugee camp demolishing the homes of the families of two Palestinians who stabbed and killed an Israeli near Jerusalem's Old City in December. The assailants in the December attack were shot and killed by Israeli guards, and a second Israeli died after apparently being shot mistakenly by police in the confusion. During Monday's demolitions, Palestinian demonstrators opened fire on soldiers, the army said. Soldiers tried to disperse the crowd using stun grenades and rubber bullets, then opened fire toward the "main instigators," it said. The clash came after a few days of increased violence. On Friday, a Palestinian gunman ambushed a family traveling in a car in the southern West Bank, killing an Israeli man and wounding his wife and two teenage children. The day before, a Palestinian teen stabbed a 13-year-old Israeli-American girl to death as she slept in her bedroom in a West Bank settlement. Also Monday, Israel's Shin Bet security agency said it has arrested two Palestinians who helped two Palestinian gunmen carry out a deadly shooting attack at a Tel Aviv cafe last month. The Shin Bet said the gunmen drew inspiration from the Islamic State group, but were not recruited to IS and did not receive training from it. Four Israelis were killed in the attack and others were wounded. Over the past nine months, Palestinians have carried out dozens of stabbings, shootings and attacks using cars against civilians and security forces, killing 34 Israelis and two visiting Americans. During the same period, Israeli troops as well as some armed civilians have killed about 200 Palestinians — most of them said by Israel to be attackers. Israel says the violence is fueled by a Palestinian campaign of incitement, and a glorification of attacks by Palestinians on social media. Palestinians say the violence stems from frustration at nearly five decades of Israeli rule in territory they claim for a state.