Oman’s Sohar Aluminium said on Wednesday it was restarting production after an interruption in August, and was working to return to full production as soon as possible.

But the smelter may need four to six months to get back to full operation, an industry source told Reuters on Wednesday.

“About 130,000 to 150,000 tons of supply will likely be lost,” the source said.

Sohar said last month an “incident” interrupted operations on Aug. 4, without giving more details.