The world’s top three platinum mines are using technology to sidestep a militant South African mine workers’ union and get miners back to work in the country’s worst mining strike, Reuters reports in the ChicagoTribune.

The logistical challenge for the companies — Anglo American Platinum (Amplats), Impala Platinum (Implats) and Lonmin — was how to communicate with 70,000 mine workers around the country afraid to return to work due to violence.

Many workers sat out the four-month strike at home in rural areas such as the Eastern Cape.

Besides text messages, email and local language radio slots, the companies asked tribal elders to help sell their pay offers to strikers.

Xolile Ndevu is general secretary of the Congress of Traditional Leaders of South Africa and one of the people asked to help negotiate after talks deadlocked.

“The miners want to go back to work but they are afraid of being killed,” Ndevu said.

The Association of Mineworkers and Construction Union (AMCU), has a reputation for crushing dissent by taking decisions via a show of hands at meetings, and enforcing its will by violence, ChicagoTribune reports.

Most of the workforce at the strike-affected mines are AMCU members. Others are members of the National Union of Mineworkers (NUM) — the traditional mining industry union — or Solidarity, which represents white-collar workers. AMCU ousted NUM on the platinum belt in a bloody turf war in 2012.

The companies said modern technology was fruitful and a majority of miners said electronically they want to return to work.

The No. 1 way of communicating was via mass mobile phone messages in English, Xhosa and Sotho, Reuters reports. South Africa has 11 official languages and many miners speak little or no English. They were asked to respond to wage offers with a “yes” or “no” reply.

“I want to go back to work but I have security concerns,” one AMCU member at Lonmin told Reuters at a mine recruiting office in Mthatha, a provincial capital 435 miles south of Johannesburg.

He did not give his name for fear he would be hurt if AMCU’s leaders found out.

Four miners were killed around the Rustenburg platinum mines on the weekend and the three companies reported 20 incidents of intimidation over the previous two days.

AMCU denies intimidation accusations and says most of its members rejected the wage offer.

Amplats CEO Chris Griffith said Tuesday the mines had polled miners using interactive voice message technology in a variety of languages and reached a definitive answer.

“It’s pretty much like a call center that calls you and you can choose Options 1, 2 or 3,” he told Johannesburg’s Talk Radio 702. “We put out very simple messages: Do you want to come back to work? Do you want to accept the offer on the table? And the majority of employees in Lonmin, Implats and Amplats are saying to us, ‘We want to come back to work.'”

Amplats said many of its workers had already returned to Rustenburg, where police have deployed in force to try and prevent violence with AMCU die-hards. Bus vouchers are being given to mine workers still in the Eastern Cape.