Gaza, Oct 12 : A senior Hamas official has said that it was too early to exchange Israeli hostages who were taken captive after the militant group launched its surprise attack on the Jewish nation on October 7. Speaking to CNN on Wednesday from Doha, Izzat al-Risheq said: "We will only discuss this issue when the Israeli aggression against our people ends." Denying that Hamas had any help from Iran or the Hezbollah in Lebanon in executing the large-scale unprecedented assault on Israel, the official said: "I say it very clearly that this operation was a 100 per cent Hamas operation without any help from any regional party." On Monday, Israel's ambassador to the UN had announced that as many as 150 people, including senior army officers, were being held hostage by the group across Gaza. The same day, Abu Obaida, the spokesperson of Hamas' armed wing Al-Qassam Brigades, said they would start executing civilian hostages if Israel targeted people in the enclave without warning. Also speaking to CNN, Israel Defense Forces (IDF) spokesman Lt. Col. Jonathan Conricus said that authorities believe that the hostages were being held underground. 'Reason dictates that they are underground. Reason also dictates that Hamas, since they planned to launch this attack and they planned to take these people hostage, reason dictates that they planned in advance locations to hide these hostages and keep them safe from Israeli intelligence, and efforts to get them out,'he said The situation with the hostages is an 'extremely sensitive and complex topic', Conricus told CNN and added that even though Israel has had 'some experience' with hostage situations, they have never dealt with anything like this. 'Not in the scope, not in the magnitude and not in the complexity of where our hostages are." Regarding an Israeli ground invasion, Conricus told CNN: "It is clear and understandable that what needs to be done is that all of Hamas' military capabilities need to be taken off the map. How that will happen, by what means, and what tactics, that is a few days in the future, maybe more than that.' /IANS