URUMQI - The airport operator and airlines in China's Xinjiang Uygur autonomous region on Thursday announced security measures have been strengthened after a foiled flight hijacking last week caused nationwide concerns.

All 16 airports in Xinjiang have raised security check levels, said a spokesman of Xinjiang Airport Group Co. Ltd, the regional airport operator. Passengers need to have all their take-on bottles and most of their baggage opened for inspection.

In particular, the disabled should present hospital-issued disability certificates if they want to bring crutches or other mobility aids on board the plane.

Passengers at Kashgar airport, in southern Xinjiang near Hotan, must check their crutches and wheelchairs in as baggage. The airport will provide them with mobility aids to help them get on board, said an airport official who asked not to be named.

The boost in security measures comes after six passengers tried to hijack a Tianjin Airline plane minutes after it took off from Hotan Airport last Friday.

According to police and witnesses' accounts, the hijackers dismantled a crutch into aluminum pipes to use as weapons. They tried to storm the cockpit but were manhandled by flight security guards and passengers.

Major airlines operating Xinjiang routes including China Southern and Hainan Airline said the incident did not affect their businesses.

Xinjiang sees a summer travel peak from July. Airports become packed with travelers, many of whom are tourists.

"In the past, passengers were asked to take off shoes and belts for security checks. But now, we have to check in hand-carry baggage as well," said Liu Jing, a tourist who flew from Kashgar to Urumqi Wednesday.

"It is definitely stricter. But as it is for our benefit, who can blame the airport?"