Sarah Neliima worked as a waitress at Friends Restaurant in Katabi town, a few kilometres from Uganda’s international airport in Entebbe. At 9pm on 19 September, Neliima, who lived nearby, finished for the day.

“That was the time she usually left work for home,” said Harriet Namusoke, a friend.

The next day, Neliima, 22, did not show up for work. She was not at home either. Concerned colleagues and relatives mounted a search.

Neliima’s body was found later that day in a banana garden, a stone’s throw from the Entebbe-Kampala highway – the 23rd woman to have been murdered in the area since June.

The spate of brutal deaths in Wakiso district is raising the spectre of a possible serial killer at work and local women are terrified. Ugandan President Yoweri Museveni made an impromptu visit this week to the affected communities, promising he would personally investigate the murders.

“We have previously dealt with and defeated more sophisticated crime, including terrorism. We shall apprehend those behind these killings,” Museveni said. “The Wanainchi [ordinary people] gave me valuable information. We shall bring an end to these senseless murders.”

There have been striking resemblances between the killings: the women were all aged between 18 and 35, each of them was raped, and all had sticks placed in their vaginas.

A list of the women murdered around the Kampala, published in the newspaper New Vision. Photograph: Alon Mwesigwa

Some of the murdered women were known to be sex workers, and at least two were students.

Authorities have blamed the murders on domestic violence, ritual sacrifice or a drugs gangs working in the area. After the first eight bodies were found there were reports of a man confessing to killing women on the orders of a local businessman. But Asan Kasingye, a police spokesperson, told the Guardian on Thursday that while they have so far arrested and charged 13 people in connection with the killings – the latest, a businessman, was apprehended on Wednesday – yet the murders continue.

More than 400 police officers have been deployed to the area and a curfew has been imposed. The presidential residence is in Entebbe and, with the airport nearby, the area already has a heavy security presence.

Among the other victims are 18-year-old high school student Norah Wanyama, whose body was found in a banana plantation on 21 July in Nkumba Central, a village in Entebbe.

Mother of four Julia Nalule’s body was missing for more than a month before her body was found. She had left her home to supervise her bricklaying business, but never returned.

On 5 September, parliament was unceremoniously adjourned after government ministers were unable to offer any explanation for the murders. Two days later, internal affairs minister Jeje Odongo told legislators the deaths were the result of ritual sacrifices – an explanation dismissed by activists as simplistic and insensitive to the victims and their families.

Uganda’s inspector general of police, Kale Kayihura, had blamed the murders on domestic violence. On Thursday he linked them to drug abuse, alcoholism, youth unemployment – which in most areas affects more than half of all 18-24-year-olds in the country – and organised crime.

Women’s rights activists have called on the government to account for the failure of the authorities to find the killers. They have created a hashtag, #NotAnotherWoman, and called on Ugandans to observe a day of mourning.

Uganda Women’s Network posted: “I am the unknown woman, killed in cold blood, if government had done more to protect me, I’d be alive, to fend for my kids.”

Action for Development, a local advocacy group, said: “It’s the responsibility of the state to ensure safety for us all. Lives [have been] cut short because they are women.”

Liliane Byarugaba, a member of the Uganda Association of Women Lawyers, told reporters in Kampala earlier this month: “We demand a combined security report from the security arms of government led by the police about the causes of the murders.”

Kayihura said: “With more vigilance and community policing we’ll be able to get those behind these killings.”

He said the police had formed lookout teams among local people to help identify people they suspect to be behind the murders.

But this has done little to calm the fears of women. Annette Belinda, a retailer in Entebbe, said: “We are scared. We have been told not to move out of our houses after 10pm.”

Few residents have faith that the killings will stop.

“I have stopped moving about at night. He could be a serial killer. I don’t know where he will strike next,” said Deo Busulwa, who lives a stone’s throw from the canalside location where the body of mother-of-two Maria Nabilawa was found earlier this month.