Last Updated Nov 16, 2015 4:39 AM EST
Belgium's federal prosecutor's office said Monday that five of the seven people who were arrested over the weekend because of possible links to the Paris attacks have been released. The office also said that a raid in Molenbeek during much of Monday did not yield any terror arrests.
CBS News correspondent Elizabeth Palmer reports that security services are moving in aggressively to find the network behind Friday's attack. Meanwhile French reports say the mastermind of the operation, Abdelhamid Abaaoud, is a Belgian citizen of Moroccan descent who had gone fight in Syria, where he's believed to be now.
Earlier this year, he was named as the suspected ringleader of a plot to kill police in Belgium.
Police have issued an international arrest warrant for a suspected terrorist still on the loose.
The other suspects include Sami Amimour, just identified Monday morning, who allegedly attacked the concert hall. He's French and was already known to the security services for his links to extremist criminals.
Ahmad Almohammad -- possibly not his real name -- was one of the suicide bombers. He slipped into Europe on a false passport last month. He is among the thousands of asylum seekers who have come ashore in Greece.
Finally, the brother of the logistics man -- Ibrahim Abdeslam -- is widely reported, though not officially confirmed, to have gunned down restaurant customers in central Paris, and then blown himself up.
All weekend, family members came to the edge of the police cordon around the concert hall where their beloved sons and daughters died. Shock dissolved into anguish.
Nearby, where floral tributes are piling up, a rabbi and two imams came to light candles and speak to the crowd.
"Not in our name," one said.
Now is the time, said one imam, for French Muslims to take a clear stand against any form of terrorism.
There is a plea to unite France's multicultural society, now fractured and bruised by 129 senseless deaths.