BBC News with Maria Marshall.

The Israeli Prime Minister Benjamin Netanyahu had said Israel must be prepared for a long campaign in Gaza. Mr. Netanyahu said Israel would continue to act until its stated aim to destroy a network of tunnels had been achieved.

We knew that we would have a difficult day, this is a difficult and painful day, time and determination are required in order to continue and to struggle against a murderous terrorist group that aspires destroyers. I said it before and I repeat. We must be prepared for a protracted campaign.

Earlier Palestinian officials said eight children and two adults were killed in an Israeli airstrike on a park in Gaza, Martin Patience sent this report.

The children were playing outdoors during a brief lull in the fighting. One eyewitness said they had a huge explosion. He then rushed from his home and found the bodies of children scattered in the street. Hamas says the children were killed by an Israeli airstrike, but Israel denies this, saying the blast was caused when Palestinian militants misfired a rocket. This night fell all over the territory, flares from the Israeli military, lit up the sky, in a sign that Israel's operation may be about to expand. Thousands of Palestinians have been told to leave their homes.

Dutch and Australian forensic experts say they've been prevented for a second day from reaching the wreckage of Flight MH17 in Ukraine by heavy fighting between government and pro-Russia forces. The head of the Dutch recovery mission Pieter-Jaap Aalbersberg says they are keen to get on with the investigation.

It is frustrating to have to wait to do the job they came to do. Their motivations come from the deep conviction that the relatives, in all the different countries, are entitled to have their lost ones and their personal affects return to them. If the experts find the remains, they will be recovered immediately. We will not leave any remains behind.

The government said its troops were advancing towards the area where the plane came down, but denied there were fighting in the immediate crash zone. Separatist leaders in the eastern city of Donetsk said the self-styled Prime Minister Alexander Borodai has left for his native Russia. Another militant, Vladimir Antufayyev, who moved there recently, now says he is in charge.

President Obama and European Union leaders have agreed to impose further sanctions on Russia because they say they've seen no evidence that President Putin is preparing to change policy on eastern Ukraine. Details will be finalized at a meeting of European Union officials on Tuesday. But it's thought the new measures will target the Russian defense, energy and banking sectors. On Saturday, the EU expanded its blacklist of Russian individuals and organizations, subject to asset freezes and travel bans.

World News from the BBC.

The Libyan authorities say a huge fire at an oil depot near Tripoli Airport is raging out of control, and has spread to a second tank. A Libya oil company spokesman said firefighters withdrawn from the site as fighting resumed in the area. The government has blamed clashes between rival militias for igniting the blaze.

The French Foreign Minister Laurent Fabius has confirmed that the pilots of a plane that crashed in Mali last Thursday had asked for a change of course. Mr. Fabius said that the crew of the Air Algerie plane flying from Burkina Faso had then requested permission to turn back before all contact was lost. He said no theory about the cause of the crash had been ruled out.

Russia's Finance Ministry has vowed to challenge an International Court ruling that Moscow must pay more the 50 billion dollars in compensation to shareholders of the former Russian oil giant Yukos. Our economic correspondent Andrew Walker has more on the case.

Yukos was one of the giants of the energy industry that emerged at the end of the Soviet Union. But the company collapsed as its chief executive Mikhail Khodorkovsky was arrested, tried and imprisoned for theft and tax evasion, and his assets were acquired by a state-owned oil company. The ruling of the Permanent Court of Arbitration in The Hague calls the failure of Yukos a devious and calculated expropriation. He says the court was used to incarcerate a man who gave signs of becoming a political competitor to President Putin. Mr. Khodorkovsky, who was no longer in prison, welcomed the ruling, but says he will not benefit financially. Russian officials have said they would appeal and described the ruling as flawed and politically biased.

A man in Britain has admitted in court to taking more 500,000 dollars which had been donated to the armed forces charity Help for Heroes. The man recruited teams of workers to collect the money at supermarkets around the country, and then put it into his own bank account.

BBC World Service News.