Israeli Prime Minister Benjamin Netanyahu warned Hamas on Sunday that if it continues the violent attacks against Israel, "it will be stopped in a very painful way".Netanyahu made the remarks at the weekly Israeli Cabinet meeting in Jerusalem, Xinhua reported.The Prime Minister made his threat as a result of the increased riots by Palestinian demonstrators near the security border fence in the Gaza Strip.Last Friday, some 15,000 demonstrated in locations near the fence, burning tires and hurling rocks, explosive devices and grenades at Israeli troops.During the riots, according to Palestinian reports, seven demonstrators were killed, including three who crossed the fence and approached a post of the Israeli army.Netanyahu noted that "Hamas, apparently, has not internalized the message. We are very close to a different kind of activity that will include very powerful blows."Meanwhile, Israeli Minister of Defence Avigdor Lieberman told the website "Ynet" that "after months of rioting and burning of fields, we have reached the point that we must strike the hardest blow possible on Hamas."