Russian President Vladimir Putin on Tuesday voiced concern over the "catastrophic increase" in the number of civilians killed since fighting between Israel and the Hamas militant group erupted over the weekend. During a telephone call with his Turkish counterpart Recep Tayyip Erdogan, "emphasis was placed on the sharply worsening situation in the Israeli-Palestinian conflict zone," the Kremlin said in a statement."Deep concern was expressed about the continuing escalation of violence and the catastrophic increase in the number of civilian casualties," it added.Putin and Erdogan reiterated the need for "an immediate ceasefire" during their conversation, as well as for "the resumption of the negotiation process."In its turn, the Turkish presidency stated the two leaders discussed "the alarming developments of the Israeli-Palestinian conflict and the measures to be taken in order to avoid an escalation."Erdogan also said that it was "regrettable to target civilian installations and that Turkey doesn't welcome such acts."Since fighters from the Hamas militant group attacked Israel on Saturday, the Israeli military has hammered the tiny coastal enclave of Gaza, where civilians have scrambled to find safety.Israeli Prime Minister Benjamin Netanyahu vowed to defeat Hamas "with force, lots of force."Earlier on Tuesday, Putin called the creation of a Palestinian state "necessary" to reseolve the decades-long conflict and argued that the new war between Israel and Hamas demonstrated the "failure" of US policy in the Middle East.