Pakistani security source cites intelligence about possibility of attack being planned . A possible London -style attack in or near Mumbai is a concern , the Metropolitan Police learns . CNN understands that the intelligence operation concerns a possible Mumbai-style attack , the source said . second source : Increased security precautions in effect at transportation hubs . Security threat level hiked to `` severe '' for civil aviation , London transport .
Pakistani security source cites intelligence about possibility of attack being planned . A possible London -style attack in or near Mumbai is a concern , the Metropolitan Police learns . second source : Increased security precautions in effect at transportation hubs . Security threat level hiked to `` severe '' for civil aviation , London transport .