A Foxconn factory in China resumed production Tuesday after a brawl by workers highlighted tensions that labor groups say were worsened by the pressure of a new iPhone launch, reports the “Associated Press” (http://macte.ch/hFyhH).

Foxconn Technology Group and police said the cause of the unrest Sunday night was under investigation, but labor activists said the rollout of the iPhone 5 has led to longer working hours and more pressure on workers. Foxconn and police said as many as 2,000 employees were involved in the brawl and 40 people were reported injured, notes the “AP.”