Beijing police have increased helicopter patrols since May as an anti-terror precaution, according to the municipal public security authorities.
Yang Dongfeng, captain of the air police team, said eight patrol routes cover almost all transport hubs, major urban centers, open markets, parks and checkpoints on highway entrances to Beijing.
The Beijing helicopter police team was formed in 2007 for the Olympic Games and now has nine pilots and five helicopters. Five other new pilots are being trained abroad.
The air police collect evidence, trail criminal suspects, support ground operations in combating terrorism, transfer policemen and facilities and assist traffic control.
"With helicopter monitoring, we can see the moves of suspects and even vehicle registration plates from the sky," said Yang.
Besides the public security mission, the team also take part in environmental monitoring, aerial surveys and mapping, added Yang.
Following recent terrorist attacks, China has increased armed patrols and reinforced public security. Besides increased air patrols, Beijing has more armed patrol vehicles and police dogs on the streets.