In the West Bank settlements, two men shot the guard from a car, the Israeli army said, and several people were subsequently detained.
One of the main military groups in the West Bank, the Aksa Martyrs, took responsibility for the attack.
The 20-30-year-old man was killed in his post near Ariel’s city on Friday night, the army said. After the guard’s death, several roads were closed in the area, trying to find the two men who had left the scene of the attack.
It has been reported in the Israeli media that both attackers were Palestinians.
The Israeli army announced on Saturday that several people had been detained and weapons removed in Brooklyn and the Balat refugee camp.
Earlier, a Palestinian health ministry said a 20-30-year-old man had been shot in the chest and died during an Israeli army operation north of the West Bank in Azuna.
Tensions have escalated in the region following a series of attacks and new clashes on the Temple Mount in Jerusalem’s Old City.
42 people were injured in another clash on Temple Mount on Friday, the last Muslim holy month of Ramadan, according to the Palestinian Red Crescent Movement.
Nearly 300 Palestinians have been injured in the clashes in more than two weeks.
The violence in Israeli-annexed East Jerusalem has raised fears of a new armed conflict. Last year, similar unrest at the Aqsa Mosque escalated into an 11-day war between Israel and the Palestinian militant group Hamas.
The Temple Mount, home to the Cliff Dome Mosque and the Aksa Mosque, is the third holiest site in Islam, where many believers come during Ramadan. It is also a Jewish shrine, with two Jewish temples.
The Temple Mount is under Muslim control and Israel is responsible for its security. An agreement with Muslim officials stipulates that Jews may visit the shrine but may not pray there. Palestinians accuse Israel of trying to extend Jewish rights to the sanctuary.