Police investigating an arson attack on part of Birmingham's rail network say they are following new leads in the hunt for the offenders. Thousands of commuters travelling into Moor Street and Snow Hill were stranded following the attack on signalling equipment in Small Heath in September.
British Transport Police have since questioned almost 100 people.
Officers said they are still keen to trace three boys they think may have witnessed the attacks.
Three Asian youngsters, aged about 14 and 15, were seen at Small Heath Highway on 25 September.