A bomb disposal team are investigating a software firm in Small Heath where it is believed two men arrested in connection with a series of explosions at mosques in the West Midlands were on work placement.
The bosses of software firm, Delcam, confirmed that the two Ukrainian men, aged 22 and 25, were students on placement there but were not employed by them.
"I would like to thank the public for their ongoing support and the way in which they responded to our appeal.
I appreciate that there is significant disruption whilst experts search and check this area. These road closures are essential to ensure that we keep everyone safe.
Investigations like this are complex and we need to ensure that we obtain every piece of information or forensic evidence possible. This could take some time. What I can say is that we will endeavour to return the local area to normal as quickly as possible."
Areas of Small Heath in Birmingham remain cordoned off after two Eastern European men were arrested on suspicion of terrorism over the Walsall mosque attack in June.
The 25-year-old and 22-year-old were arrested by detectives from the West Midlands Counter Terrorism Unit on Talbot Way on suspicion of being involved in the commission, preparation or instigation of an act of terrorism.
The first was arrested after being spotted by officers working in the local area and the second was arrested at a property nearby.
An area around Talbot Way, Small Heath is in the process of being searched, but as a precaution, properties around the industrial estate have been temporarily evacuated.