At least 16 militants have been killed and 100 passengers were freed as of Wednesday morning, local media reported. The BBC has not been able to independently verify those figures. Among those released are 17 injured passengers, who have been admitted to hospital for treatment.

Pakistani security forces are carrying out a rescue operation to free dozens of passengers taken hostage by separatist militants who hijacked their train in the southwest of the country on Tuesday. Here is a look at what happened,