Image copyright AFP Image caption Bangladesh police chief Javed Patwary asked people to ignore false child abduction rumours

Eight people have been killed in mob attacks in Bangladesh after false rumours about child abductions spread online, police have said.

The victims were targeted over rumours that human sacrifices were needed to build the Padma Bridge, south of the capital Dhaka.

Rumours claimed children were being beheaded as offerings to the $3bn (£2.4bn) project.

Vigilante groups in turn lynched people they suspected of kidnappings.

None of the victims were involved in child abduction, police chief Javed Patwary told reporters in Dhaka.

Taslima Begum, a single mother of two children aged 11 and four, was among the eight people killed. More than 30 people were reportedly attacked over the rumours.

Eight people were arrested over Ms Begum's murder, and five others are being held in connection with the rumours, according to AFP news agency.

Who are the victims?

The three most recent killings happened last week, police say.

On Saturday, Ms Begum, 42, was beaten to death outside a school in Dhaka by a mob who suspected her of being a child kidnapper.

Image copyright Police handout Image caption Mum-of-two Taslima Begum was among the victims

Locals became suspicious of Ms Begum after she visited the school to enquire about the admission of her children, witnesses told bdnews24.com, a Bangladeshi online newspaper.

A teacher who witnessed her murder told the website "we could do nothing against the wave of people" attacking her.

The other victims were a man in his 30s, beaten by a mob in Keraniganj last Thursday, and a woman in her 30s, assaulted by a mob in Savar on Saturday, bdnews24.com reports.

How did the rumours start?

The rumours, local media have reported, started circulating on social media networks about two weeks ago. They were mostly spread in posts on Facebook and videos on YouTube.

One report claimed a young man had been found allegedly carrying the severed head of a child in Bangladesh's northern district of Netrokona.

The posts on Facebook, according to local media, say that "child abductors are on the prowl to collect heads and blood for the construction of Padma Bridge".

Image copyright Wikipedia Commons Image caption A picture of the Padma Bridge, south of Bangladesh's capital, Dhaka, under construction

The BBC has seen several posts and videos on Facebook perpetuating the rumour.

At a press conference on Wednesday, Mr Patwary said the posts were being spread deliberately to "create unrest in the country", without elaborating on the culprits.

What are the authorities doing?

Police are attempting to quell the rumours by raising awareness of them through the media and warning people not to take the law into their own hands.

At least 25 YouTube channels, 60 Facebook pages and 10 websites accused of spreading the rumours have been shut down, Mr Patwary said.

In rural towns, officers are using loudspeakers in an attempt to drown out the rumours.

"We are building awareness about the rumour and ask people not to get panicked," a police chief in north-western Chapainawabganj district said.

Media playback is unsupported on your device Media caption False rumours shared on social media in India sparked similar mob violence in India in 2018

Local media say similar mob lynchings in Bangladesh, also linked to the construction of a bridge, happened in 2010.

The most recent episode is reminiscent of mob-related violence and killings in India following the spread of false rumours about child abduction on messaging app WhatsApp.