The Israeli army on Thursday said it was investigating the killing of two Palestinians by Israeli forces during clashes in the West Bank earlier in the day.

Muhammad Abu Thahr, 22, and Nadim Nuwara, 17, were shot dead by Israeli security forces in one of several violent clashes that erupted on Nakba Day, or the day of "catastrophe" in Arabic, an annual commemoration of Palestinian lament over Israel's establishment in 1948 and their displacement during the war in its wake, Palestinian media reported.

Israeli news site Ynet quoted Palestinian medical officials who said both men were shot in the heart. They were demonstrating outside the Israeli Ofer prison near Ramallah.

"Earlier today, a violent riot involving about 150 Palestinians erupted in Beitunia. Security forces arrived at the scene and attempted to disperse the crowd with riot dispersal means, including rubber tipped bullets," the Israeli army said in a statement, adding that "reports of Palestinian casualties are currently being reviewed."