Workers are increasingly reporting for duty at the stoppage-hit operations of Anglo American Platinum Ltd. in South Africa as incidents of violence or intimidation against non-striking employees subside, minority unions said.

More than 90 percent of members belonging to smaller trade union UASA are at work, Franz Stehring, its head of mining, said by phone today. The Association of Mineworkers and Construction Union, the main labor organization at the world’s largest platinum producer, called a strike on Jan. 23 that has halted most of the Anglo American Plc unit’s operations. Less then half of UASA’s members went to work immediately after the strike was called, Stehring said.

“The intimidation definitely is a lot less,” Stehring said. The union represents about 12 percent of workers at the strike-disrupted mines of Amplats, as the Johannesburg-based company is known, he said.

An AMCU official was killed during a clash with police in February and two others were arrested for the attempted murder of a worker in April after more than 70,000 members of the union went on strike at mines owned by Amplats, Impala Platinum Holdings Ltd. and Lonmin Plc. The world’s three biggest producers have lost 17 billion rand ($1.6 billion) in revenue because of the country’s longest mining strike, now in its 16th week, while employees have forfeited 7.6 billion rand in wages, according to a website run by the companies.

Offer Rejected

The union has rejected the producers’ latest offer of 12,500 rand a month by 2017 including benefits, instead demanding that amount in base pay, which excludes allowances.

“The members are not returning to work without the settlement” of a 12,500 basic wage in four years, AMCU President Joseph Mathunjwa said by phone after addressing members at Lonmin’s Marikana operations.

Members of the National Union of Mineworkers haven’t reported any fresh attacks since some homes were petrol bombed last month, Livuwhani Mammburu, a spokesman for the union, said by phone.

The employee attendance rate at the start of the strike was about 10 percent, Amplats said in a statement on Jan. 24. The company’s spokeswoman, Mpumi Sithole, couldn’t be immediately reached for comment today.

Lonmin asked workers to decide by yesterday whether they would accept the pay deal and to report for duty next week.

Resumption Possible

“All things being equal, and we have the right skills mix and numbers by 14 May, then next month might see production coming through,” Sue Vey, a spokeswoman for the company, said in an e-mail. “We will have to wait and see though.”

Impala is the only one of the three producers to have shut down operations completely because of the strike. The company is also polling workers by text message, though the results won’t be disclosed before May 13, Johan Theron, an Impala spokesman, said in an e-mail.

“This does not imply that the mine would be re-opened anytime soon,” he said. “It will, however, give us an accurate and unbiased assessment of the number of employees and skills mix across all working areas that support the offer.”