Penelope Cruz and Javier Bardem condemn the strikes on Gaza

In an open letter, the couple demanded “a stronger response to stop the military operation, The Independent reported.

Four weeks after Israel launched its operation in Gaza Strip, more than 1,200 Palestinian civilians and children have been killed.

The letter, printed by Europa Press and other Spanish news outlets, reads: "Gaza is living through horror these days, besieged and attacked by land, sea and air.

"Palestinians' homes are being destroyed, they are being denied water, electricity [and] free movement to their hospitals, schools and fields while the international community does nothing."

It also demanded an immediate ceasefire by “Israel Occupation Forces” and urged Israel to "lift the blockade, which the Gaza Strip has suffered for more than a decade".

"Humiliates, detains, and tramples on the rights of the Palestinian population in all of the West Bank every day, also causing many deaths", was one of the predicaments echoed in the letter.

It was reported that other signatories include directors Pedro Almodovar and Benito Zambrano, actors Eduardo Noriega, Rosa Maria Sarda and Lola Herrera, and two musicians Nacho Campillo and Amaral.

Understandably, the letter caused a stir of outrage from Israeli supporters on Twitter.

US-based Jewish human rights group, The Simon Wiessenthal Center responded by saying Israel "did not start this war".

"It did what every country on this planet, including Spain, would do if hundreds of rockets were hurled at their population centres by an internationally known terrorist organisation," said its founder Rabbi Marvin Hier, in a report by The Independent.