The head of the African Union Commission (AUC) on Sunday condemned Israeli "airstrike attacks" in the Gaza Strip as violence escalates in the troubled region with 31 Palestinians reported dead.

"(AUC Chairperson) Moussa Faki Mahamat strongly condemns the continued airstrike attacks by Israel on Gaza that have killed more than 30 Palestinian civilians, including 6 children," an AU statement said.

The "targeting of civilians and the continued illegal occupation by Israeli security forces of the Occupied Territories, are in stark violation of international law, and complicate the search for a just and lasting solution", the statement said.

The recent fighting is the worst in Gaza since a war last year devastated the impoverished coastal territory, home to some 2.3 million Palestinians, and forced Israelis to seek shelter from rockets.

Israel has stepped up its bombardments of positions of the Islamic Jihad, an Iran-backed group, and the group has fired over 500 rockets in return.

The relationship with Israel is a rare point of contention for the AU, a body that values consensus, with powerful member states, notably South Africa, loudly protesting a decision by Faki last year to accept Israel's accreditation to the bloc as an observer.

The decision was a major diplomatic win for Israel, but opposing member nations said it contradicted numerous AU statements – including from Faki himself – backing the Palestinian territories.

In its statement on Sunday, the AU reiterated its support for "the Palestinian people in their legitimate quest for an independent and sovereign State" with East Jerusalem as its capital.