Voters in East Derry are expected to know who has been elected as MP in the early hours of Friday, after the Foyle result in the 2015 Westminster General Election is declared.
The 76 polling stations across the constituency closed at 10pm, and ballot boxes are now being prepared for transport to Templemore Complex in Derry, where the counting of Foyle votes started at approximately 10.15pm.
The result for East Derry - which has seven candidates - is expected at around 3am on Friday, if not sooner.
There is tight security earlier outside Templemore Complex with the steady sound of a helicopter hovering.
Police were visible outside the Complex, and everyone entering the complex has to go through airport-style security.
The atmosphere is tense inside the hall where the count is proceeding.
The seven candidates fighting the 2015 Westminster Election are Caoimhe Archibald (Sinn Fein), Yvonne Boyle (Alliance), Gregory Campbell (DUP), William McCandless (UUP), Gerry Mullan (SDLP), Neil Paine (Cannabis is Safer than Alcohol) and Elizabeth St Clair-Legge (Conservatives).
Earlier in the day, candidates including Caoimhe Archibald and Gerry Mullan, cast their votes.