Turkey's powerful president, Recep Tayyip Erdogan, will go head to head with his opposition rival in a run-off vote, the supreme election council has confirmed.

Mr Erdogan led the first round with 49.51% of the vote, its chairman said.

Although he had a clear lead over his main challenger Kemal Kilicdaroglu, who polled 44.88%, he needed more than half the vote to win the race outright.

A second round will go ahead on 28 May, with Mr Erdogan the clear favourite.

Shortly before the announcement by election council leader Ahmet Yener, the president's rival appealed to supporters not to "fall into despair" and to stand and take on the election together.

But it was not immediately obvious how the opposition Nation Alliance could narrow a margin of almost five points in just two weeks. Although the third candidate, ultranationalist Sinan Ogan, polled 5.17% it seemed unlikely that all his voters would switch to the centre-left-led opposition.

Mr Erdogan has been in power in Turkey for more than 20 years, first as prime minister and then as president, extending his powers still further after a failed coup in 2016.

Many opinion polls had suggested his rival was on course to win the first round, and Erdogan supporters celebrated outside party headquarters in Ankara long into the night.

Addressing them from the balcony, he told them he had won 2.6 million more votes than his chief rival.

With Mr Kilicdaroglu as candidate, the opposition was seen as having its best chance so far at removing him from power. It drew together a broad-based alliance of parties and offered an end to soaring inflation and Mr Erdogan's system of an all-powerful presidency.

But initial confidence in victory turned to disappointment and the opposition leader did his best to rally supporters by declaring "we will absolutely win in the second round".