GAZA, Oct 29 (Reuters) - Israeli forces attacked an Islamic Jihad training camp in the southern Gaza Strip on Saturday, killing a top commander and at least four other people, officials on both sides said.

The strike in Rafah, a town on Gaza's border with Egypt, followed a Palestinian rocket salvo on Thursday which landed deep in Israel but caused no casualties.

Islamic Jihad said an explosion in the training camp killed Ahmed al-Sheikh Khalil, a munitions expert and one of its top commanders, as well as four comrades. An Islamic Jihad source said the dead may include senior figures other than Khalil.

Those targeted were a group of leaders, the source said.

Doctors and officials from Gaza's ruling Islamist Hamas said five people died in an explosion in the camp, and two others were hurt. Witnesses saw Israeli helicopters overhead.

In Jerusalem, an Israeli military spokesman confirmed there had been an attack but did not immediately elaborate.

Islamic Jihad, a sometime Hamas ally, has chafed at recent efforts by the more powerful faction to impose de facto ceasefires with Israel. (Reporting by Nidal al-Mughrabi; Writing by Dan Williams)