Regional leaders have called on Democratic Republic of Congo rebel group M23 to end hostilities and leave a key eastern town they seized in a rampant advance that has sparked fears of a wider conflict.br br The meeting of east African heads of state went forward without a key player - Rwandan President Paul Kagame, whose country the United Nations accuses of backing the rebels - and wrapped up after less than an hour.br br Al Jazeera's correspondents report.