Dakar (AFP) - Turnout was low for Senegal's controversial referendum on sweeping constitutional reforms on Sunday, including cutting the presidential term from seven to five years.

There were no queues and few voters visible in polling stations visited by AFP in areas of the capital in the early morning. The situation was much the same after midday.

No official turnout was immediately given after polls closed at 1800 GMT, but it was hovering around 25 percent in the afternoon.

"Voters are trickling in," said an official in a polling station. An Electoral Commission spokesman added: "Enthusiasm is not as high as during legislative or presidential elections."

The first official results are expected on Monday at the earliest.

The referendum caused controversy as President Macky Sall was elected in 2012 partly on a platform to reduce the presidential mandate from seven years to five.

Sall had said reducing his own mandate would set an example within Africa, where many leaders cling to power beyond their allotted term.

But Senegal's top court rejected his proposal in February, triggering a referendum to allow the reforms to come into force once Sall leaves office -- due in 2019 in the event of a "Yes" vote.

Opposition parties and several civil society groups urged Senegalese to vote "No", saying Sall reneged on his promise to leave office early and criticising the referendum as a cop-out.

The referendum has became a de facto Yes/No vote on Sall's popularity, eclipsing more than a dozen other proposed points of reform to the constitution.