Original sentence: In an unprecedented development on May 15, thousands of people, mostly Palestinian refugees from Lebanon, the West Bank, Gaza Strip and Syria, marched towards and attempted to cross the ceasefire borders with Israel, and several Palestinians were killed as the Israeli Defense Forces tried to hold them back across the line
Edited sentence: In an unprecedented development on May 15, thousands of people, mostly Palestinian refugees from Lebanon, the West Bank, Gaza Strip and Syria, marched towards and attempted to cross the temporary ceasefire borders with Israel, and were met with lethal force and riot-control tactics