Israel's air force raided a Hamas training camp in the Gaza Strip overnight Sunday, without causing any injuries, witnesses said.

The target was in the Gaza refugee camp of Nusseirat.

In recent days, Palestinian activists have fired rockets into southern Israel from the Gaza Strip, without any casualties, according to the Israeli army.

A radical Salafist splinter group has claimed responsibility for some of the attacks.

Despite an informal truce between Hamas and Israel, tensions flare periodically on the Gaza-Israel border, with Palestinian militants firing rockets into the Jewish state and the Israeli military launching retaliatory air strikes on the Palestinian territory.

The last major flare-up was in June, when militants fired more than 150 rockets at southern Israel, wounding five people, and Israel hit back with air strikes that killed 15 Palestinians.