The Iranian authorities have not allowed her family to visit her, or revealed the reason for her arrest.
The authorities had made no arrest last night and did not reveal the contractor's identity.
Local authorities revealed that most of the dead were men as the queue for women was separate.
Below, the suspected leaders, some of what the authorities have revealed and questions they continue to try to answer.
The authorities have never revealed how many people died.
It was held that judges have a common law discretionary authority to impose publication bans on information revealed in a criminal trial.
It was only in 1991 that the Soviet authorities revealed his fate.
The Chinese authorities have not revealed which of his activities resulted in the arrest.
But authorities have revealed no details of the explosion and have given no indication they know who is responsible.
In 2008 Chinese authorities revealed that Liddell had refused an opportunity to leave the camp and instead gave his place to a pregnant woman.