Jerusalem, Oct 10 : Hamas has specifically threatened to attack the Israeli city of Ashkelon in response to Israel's attacks on Gaza, a media report said. In a post on Telegram, Hamas said the residents of the city, just to the north of the Gaza Strip, have within hours to leave, BBC reported. More than 4,500 rockets have already been fired from Gaza into Israel since Saturday, the Israeli military says. Two foreign workers have been killed and another seriously injured in a rocket attack in the Eskhol region that borders Gaza, Israel's emergency services have just said, BBC reported. The Israeli military said it had recovered the bodies of more than 1,500 Hamas fighters inside Israel and mostly secured its border with Gaza after a night of intensified airstrikes across the enclave that destroyed infrastructure and displaced thousands, The Guardian reported. An Israeli military spokesperson said its forces were installing 'an iron wall' of tanks and helicopters along the Gaza border, ahead of an expected large-scale ground invasion of the besieged enclave, The Guardian reported. The UN agency for Palestinian refugees said that more than 187,000 people have been displaced across the Gaza Strip, with the numbers expected to rise. A spokesperson for the Israeli forces, Lt Col Richard Hecht, advised Palestinians to 'get out' of Gaza through the Rafah crossing with Egypt on its southern border, before clarifying that the crossing remained closed. Images online showed damage from an airstrike to the crossing on Monday. /IANS