A rocket was launched from the Gaza Strip toward Israel on Sunday, the Israeli army said, just hours after Israel reopened its two main crossings with the territory in a sign that cease-fire talks were progressing between Israel and Hamas.
The Israeli army said that a projectile launched from the Gaza Strip did not cross into Israeli territory, but did set off air-raid sirens in the country's south.
There was no immediate claim of responsibility, and no immediate Israeli response.
Egyptian mediators have been working in recent days to broker a cease-fire between Israel and Hamas. The talks have been repeatedly interrupted by Palestinian rocket attacks and Israeli military reprisals. The violence comes just over a week before Israeli national elections.
Earlier Sunday, Palestinian militants launched rockets into Israel overnight and the military responded with tank fire.
But Israeli and Hamas officials later confirmed that the Erez and Kerem Shalom border crossings were nonetheless opened for the first time since last Monday, when a rocket fired by Palestinian militants struck a home near Tel Aviv and touched off six days of hostilities.
The reopening of the crossings, which are used to allow people and cargo to move in and out of Gaza, signaled that the Egyptian efforts were making progress. Hamas officials say the deal would include Israel easing its blockade of Gaza in exchange for guarantees of quiet.
Four Palestinians, including three teenagers, were killed by Israeli fire on Saturday as tens of thousands of people took part in mass rally that marked the first anniversary of demonstrations along the Israel-Gaza perimeter fence.
Dozens of activists approached the fence during Saturday's demonstration, hurling stones and explosives toward Israeli forces.
Israel says it is defending its border, but has come under heavy international criticism for the large number of unarmed Palestinian demonstrators who have been shot over the past 12 months.
Nearly 200 Palestinians have been killed by Israeli fire, while an Israeli soldier was killed by a Palestinian sniper last summer.