He looked like 'a normal, well-dressed passenger', passenger Rocio Garcia told Mexican television after her release.

'We did not immediately know what happened. It was all confusion, and then they told us that the plane was being hijacked by one person,' Garcia said.

Adriana Romero, another released passenger, disagreed, noting that there was no panic.

'When we landed we were told to remain seated,' she said.

At the time, they were told that the plane was being hijacked and that negotiations were ongoing, she said.

She described the hijacker as 'a well-off man'.

'He wears a good watch, a good shirt,' Romero observed. 'He often stood up to take things out of his suitcase.'

Mexican Communications and Transport Minister Juan Molinar Horcasitas told Mexican radio that Mexico City airport was operating normally.