SENEGAL cut mobile internet access ahead of a banned march against the postponement of a presidential election, and rights groups accused the authorities of using overly repressive tactics to stifle widespread opposition to the delay. The abrupt postponement of the February 25 vote to December has plunged Senegal into crisis and intensified a backlash against what many see as an attempt to extend President Macky Sall's mandate and a threat to one of the remaining democracies in coup-hit West Africa. After deadly clashes between protesters and police late last week, the government refused to permit a silent march planned by activist groups…