Protesters asking for a fair election next month in Chad have carried out a whistling protest at their homes.
Campaigners urged people to whistle for 15 minutes in the morning at 04:30 GMT and again in the evening.
The protest was thought up as a way for people to be heard without “the risk of violence”, says organisers.
President Idriss Deby took power in a coup in 1990 and is standing for a fifth term in the presidential elections on 10 April.
A coalition of 10 civil society groups urged people to use a “citizen whistle” to demand an end to bad governance and call for political change in Chad.
Paris-based human rights campaigner AbdelKerim Koundougoumi told the BBC that this is a way of protesting when people are scared of the secret police.
“People stay in their homes and you cannot see who is doing it”.
A statement he posted on Facebook by the spokesperson of the Enough is Enough coalition, Celine Narmadji, explained that some people may not feel safe protesting.
“Express your anger from your home, without the risk of violence,” the statement said.
She went on to urge people to whistle against injustice, impunity, nepotism, cronyism, favouritism, corruption, censorship, bribery, embezzlement of public funds and “your daily suffering to get your next meal”.
It comes exactly one month before the presidential elections.
President Deby has been in power for 24 years and said, if he is re-elected in April, he will reinstate a clause limiting leaders to two terms.
Two former prime ministers, Djimrangar Dadnadji and Nourredine Delwa Kassire Koumakoye, are also candidates.
They organisers are planning to whistle again for 15 minutes at 20:00 GMT.