Djibouti's President Ismail Omar Guelleh has won an election with 97.8% of the vote, keeping him at the helm of the strategically-placed Horn of Africa nation for a sixth term, preliminary official results show.

The 78-year-old's sole challenger, Mohamed Farah Samatar, received only 2.19% of the vote in a poll that was largely boycotted by the opposition.

In power for 27 years, Guelleh had previously indicated he would step down, but he opted for re-election after the constitution was amended to remove an age limit for presidential candidates.

Guelleh's campaign centered on the narrative of maintaining stability in Djibouti, particularly in a region grappling with conflict.

Strategically situated on the Bab el-Mandeb Strait, Djibouti functions as a critical gateway to the Suez Canal, attracting military bases from countries like the US, China, France, Italy, and Japan.

Guelleh, who is only Djibouti's second president since independence in 1977, celebrated his victory at his residence, claiming it as a victory for all citizens.

Despite over 80% of registered voters participating, the election has been marred by opposition claims of inadequate political freedoms, with key opposition leaders boycotting elections since 2016.

The results were announced by the interior ministry but require validation by the constitutional council before Guelleh can formally assume office for another five-year term.