An NLD spokesman said it expected to win about 70% of seats. Party leader Aung San Suu Kyi said: "I think you all have the idea of the results."

Official results have been released for just 12 seats, all won by the NLD.

The military-backed Union Solidarity Development Party (USDP) has been in power since 2011.

"We are on track to win more than 70% of seats around the country, but the election commission has not officially confirmed yet," NLD spokesman Win Htein told AFP news agency. The 12 seats announced so far are all in Yangon.

The acting chairman of the USDP has told BBC Burmese that he has lost his own seat in the constituency of Hinthada to the NLD - seen as a key indicator of election results.

"We have to find out the reason why we lost," U Htay Oo said. "However, we do accept the results without any reservations. We still don't know the final results for sure."

Earlier, Ms Suu Kyi addressed a crowd at the NLD's headquarters in Yangon, urging them to be patient.

A quarter of the parliamentary seats are reserved for the army, and for the NLD to have the winning majority it will need at least two-thirds of the contested seats.

The BBC's Jonah Fisher in Yangon says that while this is a very big ask, it is by no means impossible if the party, which is popular in urban areas, manages to win seats in rural areas which tend to be dominated by ethnic minorities.

But Ms Suu Kyi cannot become president because the constitution bars anyone with foreign children from holding the post. Her two sons, with her late husband, are British.

Our correspondent says that if the NLD win, it will face difficulties in changing the constitution on its own as the document still gives the military considerable power, and the party would most likely nominate someone else to be president. Ms Suu Kyi has said she would be "above the president".

-BBC