Nigerians headed to the polls on Saturday to elect a new president in a knife-edge vote against a backdrop of security fears but new technology delayed the process, affecting even the outgoing president

Nigerians headed to the polls on Saturday to elect a new president in a knife-edge vote against a backdrop of security fears but new technology delayed the process, affecting even the outgoing president.
  
Boko Haram appeared to carry through their pledge to try to disrupt the vote, attacking two polling stations in the northeastern state of Gombe, leaving at least two voters dead.
  
One election official said after the shootings in Birin Bolawa and Birin Fulani: "We could hear the gunmen shouting, 'Didn't we warn you about staying away from (the) election?'"
  
Polling stations had earlier opened at 0700 GMT across the country but the late arrival of officials and materials delayed the accreditation process before voting proper from 1230 GMT.
  
Handheld technology to read biometric voter identity cards is being used for the first time, which the country's electoral commission hopes will cut voter fraud that has blighted previous elections.