Birmingham’s Bullring shopping centre remains closed for a second day after a chemical scare which led to more than 30 people needing medical treatment.

The air in the centre was monitored overnight after it closed on Thursday.

The centre opened on Friday morning but was evacuated after seven people showed symptoms. It will remain closed until further notice, a spokeswoman said.

Police said any contamination remained “unexplained” and it was not known if was from an accident or malicious act.

Ten people were taken to hospital on Thursday with many complaining of feeling dizzy and nauseous.

The centre was opened for access before the latest evacuation on Friday morning but the shops had not reopened.

A spokesman for West Midlands Ambulance Service said seven people had been “showing symptoms” on Friday. They were treated at the scene.

Louise Hamer Brown from Bull Ring Marketing said: “We are evacuated at the moment and emergency services are performing further investigations.” Edgbaston Street remains closed between Park Street and Pershore Street.

A West Midlands Police spokesman said the incident may have been caused by “some sort of petroleum-based substance” potentially contaminating the shopping centre’s ventilation or air-conditioning system.

Six security workers were treated for the effects of fumes shortly before 0400 BST on Thursday. Later, more staff complained of fumes and the centre was closed.

A triage centre was set up away from the building to treat people for symptoms such as nausea, vomiting and water eyes and dizziness, the ambulance service said. BBC.