The London Stock Exchange is investigating a human error that led to a two-hour trading disruption at its Turquoise trading platform yesterday.

Preliminary investigations indicate the error may have occurred under "suspicious circumstances" on Turquoise, a pan-European trading venue majority owned by the London Stock Exchange, according to a statement from the exchange. The error caused a trading disruption that began at 8:23 a.m. in London. Normal trading resumed at 10:30 a.m.