Israel will pay a "high price" for launching a ground invasion of the Gaza Strip, the Palestinian Hamas movement said on Thursday night.
"The start of the Israeli ground attack on Gaza is a dangerous step, the consequences of which have not been calculated," said Hamas spokesman Fawzi Barhum in a statement.
"Israel will pay a high price and Hamas is ready for the confrontation."
Israel launched a ground offensive in Gaza late Thursday to stamp out rocket attacks, the Israeli army and the office of Prime Minister Benjamin Netanyahu said.
"Following 10 days of Hamas attacks by land, air and sea, and after repeated rejections of offers to de-escalate the situation, the Israel Defence Forces (army) has initiated a ground operation within the Gaza Strip," the army said in a statement.
Netanyahu's office said the "prime minister and the defence minister ordered the army to begin a ground operation and enter Gaza to strike at the terrorist tunnels from the Gaza Strip into Israeli territory."
At least 240 Palestinians have been killed in Israeli air strikes since July 8, many of them children, medics in Gaza said, with a NGO based in the coastal enclave saying 80 percent of the deaths are civilians.
One Israeli was killed.
Hamas has turned down an Egyptian proposal for a ceasefire demanding an end to the 7-year-old siege of Gaza by Israel which has crippled life for 1.7 million Palestinians.
Senior Hamas official Ghazi Hamad had said earlier the Islamist Palestinian movement refuses to accept the Cairo proposal "in its current form" and seeks a series of conditions for a truce with Israel.
*This story was edited by Ahram Online