MyrnaM,
According to the linked article, the violence recently escalated following the attempted assassination of Rabbi Yehuda Glick by a Palestinian youth.
Glick leads the Temple Mount Faithful organization, which is dedicated to re-building the long destroyed Jєωιѕн Temple on the Temple Mount. That's a highly political, even dangerous, idea: access to the Temple Mount is controlled by Israel, but only Muslims are allowed to pray there. Both the al-Aqsa mosque and the Dome of the Rock, Muslim holy sites, are located there; allowing Jєωs access to the Western Wall and Muslims access to the Temple Mount is meant as a sort of compromise. Calling to rebuild the ancient Temple on the Mount is a way of upsetting that balance, and claiming the entirety of the holy site for Jєωs.
But not all rabbis agree that now is the time to begin rebuilding the temple.
That's considered a dangerous idea. Construction on one of Islam's holiest sites would infuriate Muslims in Israel, the Palestinian territories, and around the world. It's also an extreme position among Jєωs: most rabbis believe the temple cannot or should not be rebuilt until the Jєωιѕн Messiah comes. In addition to rebuilding the Temple, Glick also wanted to expand Jєωιѕн prayer rights on the Temple Mount, a less radical challenge to the Temple Mount status quo.