The European Parliament called on Jerusalem Thursday to open an “impartial” investigation into the death of a Palestinian prisoner in Israeli custody.

EU legislators passed a resolution calling “on the Israeli authorities promptly to open independent, impartial and transparent investigations into the circumstances of [Arafat] Jaradat’s death.”

Jaradat, 30, died while in Israel’s Megiddo Prison in February. His death, of an apparent heart attack, set off a wave of protests in the West Bank. He had been arrested a week earlier on suspicion of being involved in a rock-throwing attack, which injured an Israeli.

Israel said a joint Israeli-Palestinian autopsy found only injuries from resuscitation attempts, but the Palestinian Authority alleged Jaradat had been tortured to death.

While pledging support for Israeli security needs, the resolution also expressed “deep concern” for Israel’s handling of Palestinian prisoners and called on Jerusalem to release all Palestinian lawmakers in jail, including Marwan Barghouti.

Barghouti is serving five consecutive life sentences and an additional 40 years for terrorist activity, including a Tel Aviv bombing he planned that killed three.

The resolution also called for a European fact-finding mission on the state of Palestinian prisoners in Israeli jails, including Israel’s use of administrative detention, noting that the “issue of Palestinian prisoners and detainees has far-reaching political, social and humanitarian implications.”

The resolution came two days after President Shimon Peres became the first Israeli leader to address the Strasbourg plenary.