Updated

Hackers have targeted the website of Ghana's electoral commission ahead of the release of results from a narrowly contested presidential election.

The commission reported the incident on Twitter on Thursday, saying it deplored the "attempt to hack" the site, which was offline for a few hours early Thursday.

Despite a relatively peaceful election, tensions are growing after the main opposition New Patriotic Party on Thursday urged incumbent President John Dramani Mahama to concede defeat after the NPP's internal polling data determined the opposition was poised to win.

The incumbent party denounced the press conference, calling it "irresponsible," according to local media reports.

Election officials have urged Ghanaians to patiently await the official vote tallies and to dismiss purported results from unofficial sources.