Stalling the next release of hostages from the Gaza Strip, scheduled for the coming weekend, raises new challenges for the already tenuous six-week truce and chances for a lasting end to the war.

Hamas on Monday announced it would stop releasing Israeli hostages until further notice over what the Palestinian militant group called Israeli violations of a ceasefire agreement in Gaza, raising the risk of reigniting the conflict.

A militant spokesman said Israel had kept displaced Palestinians from returning to northern Gaza, targeted Gazans with shelling and blocked aid.