Sierra Leone's government has offered a $1,000 (£640) reward for information leading to the arrest of a gang suspected of raping and killing a girl.
The body of Hannah Bockarie, a teenage sex worker, was found last week on a beach in the capital, Freetown, with sand stuffed in her mouth.
A candlelit vigil was held on Thursday night to pay tribute to her.
The BBC's Umaru Fofana in Freetown says many were shocked after seeing images of her body on social media.
An online campaign has also been launched using hashtag #Iamhannah.
The vigil was attended by women rights activists, Ms Bockarie's parents and government and UN officials.
Sierra Leone's Gender Minister Moijueh Kaikai broke down when he spoke at the ceremony and said the matter was discussed in the cabinet.
No-one has been arrested in connection with the murder and police have not yet concluded a post-mortem.
Activists said Ms Bockarie's case reminded them of the country's civil war when rape was used a weapon, reports our correspondent.