The Israeli military says Gaza militants have launched a rocket into southern Israel.
There were no reports of damage or casualties in the Sunday morning attack. The rocket demonstrated the fragility of a ceasefire that ended Israel's devastating Gaza offensive on January 18.
Israel halted the operation after saying its goals had been achieved. But Hamas declared victory and militants have kept up sporadic attacks.
Since the ceasefire, militants have fired rockets into Israel and killed one soldier in a border attack. Israel has conducted retaliatory strikes and pounded border tunnels it says Hamas uses to smuggle in weapons from Egypt. Israeli forces have also killed three men Palestinians identified as farmers in violence along the Gaza-Israel border.