Hamas' main television station, Al Aksa, is located on the top floor of the high-rise building.
In Cairo, meanwhile, Maashal said Monday during an hourlong news conference, "Whoever started the war must end it."
He told reporters that Israeli Prime Minister Benjamin Netanyahu requested a cease-fire, a claim that Israel has denied, according to reports.
Maashal said there is a new spirit of cooperation among Palestinian factions due to the Israeli operation, which began on Nov. 14.
"Israel is the common enemy. Confrontation with the enemy is our moment of truth," he said. "We must end the political divide and unite around common institutions and around resistance to Israel. Our enemy cannot be treated with words, but only by force. No concessions should be made with Israel, given the new atmosphere in the Arab world."
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