Hong Kong protesters handed out homemade gas masks Thursday amid concerns of a potential military attack. In recent days, tensions between Hong Kong riot police and protesters have escalated, and many have been pepper sprayed or had tear gas fired at them, leading demonstrators to wear masks, protective goggles and plastic raincoats to protect themselves.

The homemade gas masks are reportedly made from water bottles, tissue, face masks and rubber bands, says CNN correspondent Andrew Stevens. Last year, protesters in Turkey also combated police tear gas with homemade gas masks, and fighters in the Free Syrian Army did the same over fears that Syrian President Bashar al-Assad's regime would use chemical weapons against them.

"Both sides were appealing for calm, and then the tear gas just exploded in the midst of everybody," CNN’s Ivan Watson said after being engulfed in tear gas during a protest in Hong Kong on Sunday. "People here have never been hit by tear gas before, and it comes as quite a shock to them -- even the use of pepper spray....This is a big shock for a city that is famed for its law and order."



Demonstrations started after China decided not to allow a fully democratic election to select the former British colony’s next leader. Instead of full suffrage for Hong Kong residents, candidates must be approved by a Communist Party nominating panel.

Protesters had given the government until Thursday to meet their demands of a free election.