By Nidal al-Mughrabi

CAIRO (Reuters) - The armed wing of Palestinian Islamist group Hamas claimed responsibility on Sunday for an attack on the Kerem Shalom crossing between Israel and Gaza, which Israeli and Palestinian media reports said had resulted in Israeli casualties.

Israel's military said 10 projectiles were launched from Rafah in southern Gaza towards the crossing, which it said was now closed to aid trucks going into the coastal enclave. However, other crossings remain open.

Hamas' armed wing said it fired rockets at an Israeli army base by the crossing, but did not confirm where it fired them from. Hamas media quoted a source close to the group saying the commercial crossing was not the target.

More than a million Palestinians are sheltering in Rafah, near the border with Egypt.

Israel has vowed to enter the southern Gaza city and flush out Hamas forces there, but has faced mounting pressure to hold fire as the operation could derail fragile humanitarian efforts in Gaza and endanger many more lives.

Sunday's attack on the crossing came as hopes dimmed for ceasefire talks underway in Cairo.