Israeli forces Thursday shot dead two Palestinians during a Nakba Day demonstration in the West Bank, prompting a Palestinian warning of a halt in security coordination with the Jewish state. The demonstration was held to mark the anniversary of the Nakba, or "catastrophe" of the 1948 establishment of the state of Israel on the former British mandate of Palestine. "The Palestinian leadership cannot remain idle in the face of Israel's violations, the latest of which was the killing of the two young Palestinians today (Thursday)" near Ramallah in the West Bank, Palestinian security spokesman Adnan al-Damiri told AFP. "And all this prompts the leadership to seriously consider a halt to security coordination with the Israeli side," he said. Security and medical sources earlier said Musaab Nuwarah, 20, and teenager Mohammed Udeh, 17, died in a Ramallah hospital after being shot in the chest during a protest outside Ofer jail near Ramallah. Israel's military said its border police had clashed with around 150 protesters, using "anti-riot methods and rubber bullets", although Damiri said live rounds were fired. Protesters calling for the release of Palestinians detained without trial set fire to tyres and hurled stones at border police, an army spokesman said. Condemning the killings, Amnesty International said Israeli forces had used "excessive, including lethal, force in response to rock-throwing protesters who could not have posed a threat to the lives of the soldiers and policemen in or near the fortified military camp". Other Palestinian rallies for Nakba Day were held in the northern city of Nablus, in Hebron in the south of the West Bank and in east Jerusalem, where police reported a clash and arrests. Hundreds of demonstrators, some carrying Palestinian flags or banners calling for refugees to be allowed to return to their former homes, also marched in the Gaza Strip near the Erez crossing with Israel. In Ramallah, where Palestinian president Mahmud Abbas and his Palestinian Authority are headquartered, people stood in silence on the streets for 66 seconds as sirens wailed. "On this 66th anniversary of the Nakba, we hope this year will be the one in which our long suffering ends," Abbas said in a speech broadcast late Wednesday. "It is time to put an end to the longest occupation in modern history and time for Israel's leaders to understand that there is no other homeland for the Palestinians but Palestine." - Months of fruitless talks - After nearly nine months of fruitless US-sponsored peace talks, Israel suspended its participation in negotiations last month when Abbas's Palestine Liberation Organisation (PLO) announced a unity deal with the Islamist movement Hamas which runs Gaza. US Secretary of State John Kerry, who met Abbas in London on Wednesday, was also to hold informal talks with Israeli negotiator Tzipi Livni in the British capital, a US official said. Prime Minister Benjamin Netanyahu on Thursday accused the Palestinians of teaching their children that Israel "should be made to disappear". The Israeli answer was to "continue building our country and our unified capital, Jerusalem", said the rightwing premier. "Another answer to the Nakba is our passing the Nation Law, clarifying to the world that Israel is the State of the Jewish people," he said in remarks relayed by his office. Netanyahu has pledged to enshrine Israel's status as the national homeland of the Jewish people in law. He has repeatedly demanded Palestinian recognition of Israel's status, but Abbas has flatly refused. In 1948, more than 760,000 Palestinians -- now estimated to number more than five million with their descendants -- fled or were driven out of their homes. Around 160,000 stayed behind and became Israeli citizens. They and their descendants currently number about 1.4 million people, or some 20 percent of Israel's population. Palestinian chief peace negotiator Saeb Erakat, in a commentary published in Israel's left-leaning daily Haaretz, said the PLO has officially recognised Israel’s right to exist since 1988. But "the concept of an exclusively Jewish state necessarily implies the negation of the Nakba", Erakat wrote.