An Israeli airstrike has demolished a high-rise building housing international media outlets in Gaza.
Three heavy missiles pounded the 12-storey building, razing it to the ground, after journalists and other tenants were evacuated from the building.
Shadow foreign secretary Lisa Nandy described the attack on the offices The Associated Press, Al-Jazeera and others as "completely unacceptable", adding that "press freedom is a fundamental right".
The strike came hours after at least 10 Palestinians, mostly children and from an extended family, were killed in an Israeli air raid on a densely populated refugee camp.
The AP news agency said the targeting of the media building is "an incredibly disturbing development" and warned the "world will know less about what is happening in Gaza because of what happened today".
Dr Mostefa Souag, acting director general of Al-Jazeera Media Network, said: "We call on the international community to condemn such barbaric actions and targeting of journalists and we demand an immediate international action to hold Israel accountable for its deliberate targeting of journalists and the media institutions."
The Israeli military said the building contained military assets belonging to Hamas, the Palestinian militant group that governs Gaza.
Ms Nandy condemned the airstrike and called for the Government to join allies in calling for a ceasefire, amid concerns the conflict could escalate into all-out war.
"The targeting of media offices in Gaza by Israeli airstrikes is completely unacceptable. Press freedom is a fundamental right," she said in a statement.
"The devastating escalation of violence, including Hamas rocket attacks on Tel Aviv and air strikes on the Gaza City refugee camp, has cost more civilian lives and we condemn it in the strongest possible terms.
"The UK must join our international partners in calling for an immediate ceasefire, an end to all rocket attacks and airstrikes, and work with both Israeli and Palestinian leaders to prevent this dangerous situation deteriorating further."
The White House told Israel that "ensuring the safety and security of journalists and independent media is a paramount responsibility".
The Foreign Office has not commented on the attack.
