A cease-fire aimed at halting months of deadly internal Palestinian violence held on its first day, but underlying tensions cast doubt on the future of the stand-down.

For the most part, gunmen from the rival groups Hamas and Fatah held their fire, observing a truce that went into effect before dawn. In the only exception, a Hamas militant was killed in the southern city of Khan Younis. Hamas blamed Fatah but did not retaliate. Palestinian Prime Minister Ismail Haniyeh of Hamas called for a total halt to the internal violence that killed 36 people over the past week alone.

Previous truce deals between Hamas and Fatah militants in Gaza have quickly collapsed into new waves of fighting, and it appeared unlikely the two sides would comply with all the terms of the current agreement.