The director of a news site critical of Senegal's government has been detained by police in Dakar over accusations he distributed information "liable to harm" national security, according to his lawyer.

Pape Ale Niang, who runs the news site Dakar Matin, is well known in Senegal for his regular columns on current affairs.

He was arrested on Sunday afternoon and detained at the central police station in Dakar over three alleged "infractions", his lawyer Cire Cledor Ly told AFP.

Niang stands accused of "having brought to the public's attention information whose disclosure is liable to harm the national defence, and of acts and manoeuvres liable to compromise public security and cause trouble", Ly said.

The third infraction relates to a "violation of professional secrecy", Ly added, denouncing the arrest as a "mountain of heresy, intimidation and an attempt to muzzle the press".

Senegal's Coordination of Press Associations, a body representing local press groups, said in a statement that it would provide "all the assistance needed" by Niang.

A police source confirmed Niang's arrest to AFP, but did not offer a reason.

According to local media, the arrest came after articles by the journalist in recent days about rape charges being faced by Senegal's main opposition leader Ousmane Sonko.

Sonko, 48, who has declared his candidacy in the 2024 presidential election, has been under judicial supervision since March 2021 over accusations he raped and threatened an employee of a beauty salon where he was getting a massage.

He appeared before a judge on Thursday for the first time in the closely watched case.

Senegal was ranked 73rd out of 180 countries on the 2022 World Press Freedom Index compiled by Reporters Without Borders.