Jerusalem, Nov 2 : The Israel Defense Forces (IDF) on Thursday claimed that the Hamas militant group's defensive lines in northern Gaza continue to 'collapse' as they retreat southwards to the centre of the besieged enclave. 'The IDF continues to advance in the Gaza City area, conducting face-to-face battles with Hamas terrorists and deepening the fighting,' CNN quoted IDF spokesman Daniel Hagari as saying in a statement. 'Our fighters continue to collapse the defensive lines of Hamas in the north of the Gaza Strip and take control of central areas," he added. Hagari further claimed that Israeli forces had 'the upper hand' in every confrontation. 'We continue to intensify the activity and move forward according to the plan and the goals we have set for ourselves. The battle is progressing as we planned," he was quoted as saying. The spokesman's claims come after the IDF had announced it was "expanding ground operations" in Gaza on Friday. In a separate statement, the Israeli military also claimed "dozens" of fatalities on the Hamas side in continued fighting, the BBC reported. The IDF said Hamas fired anti-tank missiles, detonated explosives and hurled grenades at Israeli forces. But it responded with artillery fire, tank fire, an aerial strike from a helicopter and a missile strike from a navy boat. /IANS