Israeli Prime Minister Benjamin Netanyahu has blocked millions in Qatari aid to the Gaza Strip in response to renewed border hostilities, despite the fact that the besieged enclave has faced worsening humanitarian conditions.

Weeks of relative calm in the Gaza Strip ended on Tuesday when Israel carried out airstrikes in Gaza that targeted a Hamas post, saying the attacks came after shots were fired at Israeli troops near the Israel-Gaza buffer zone. Netanyahu yesterday warned Palestinian resistance group Hamas of a "destructive and painful response," according to The Jerusalem Post newspaper. "There may be someone in Gaza who thought they could raise their heads, we are ready for any scenario and escalation," Netanyahu said during a visit to a military base in southern Israel.

Israel and the Hamas resistance group have fought three wars since 2008 and fears of a fourth round remain. However violence has abated since November as a result of an informal truce between the parties.

Under that agreement Israel has permitted Gulf state Qatar to bring in aid to the strip, including $15 million a month to pay the salaries of Hamas civil servants and provide aid to impoverished residents. The January payment had been expected to enter Gaza yesterday or today, but Netanyahu has decided to block it after the border-flare up, an Israeli official confirmed.

This is the first time that Israel has admitted to obstructing the transfer, which was already delayed by two weeks. The payment would be the third of six planned tranches, totaling $90 million, in connection with the truce. Israel's permission is required since the cash must be delivered via its territory. The truck that entered Gaza brought the first delivery out of a $60 million fuel donation by Qatar meant to provide the power plant with enough fuel to operate for six months, local sources said, as Israel's long blockade of the Gaza Strip has created chronic shortages in Palestinian health facilities.

Since 2007, the Gaza Strip has suffered under a crippling Israeli and Egyptian blockade that has gutted its economy and deprived its inhabitants of many vital commodities, including food, fuel and medicine. The cash-starved plant has been providing Gazans with only around four hours of electricity daily.