European Council chief Antonio Costa on Tuesday called for an end to the renewed violence in Gaza, after Israel unleashed its most intense strikes since a truce established two months ago.

"Shocked and saddened by the news coming from Gaza and the many civilian casualties following the Israeli airstrikes last night," said Costa, who heads the body representing the bloc's 27 states.

"Violence must stop and the terms of the cease-fire agreement must be respected. All hostages and detainees must be released, and humanitarian aid must be resumed immediately," he wrote on X.

The health ministry in Gaza said more than 400 people were killed after the strikes.

Earlier the EU's aid chief called the fresh violence "devastating."

"Civilians have endured unimaginable suffering. This must stop," commissioner Hadja Lahbib wrote on X, adding: "It is imperative to return to a cease-fire immediately."