BEIJING, May 9 -- Beijing police have launched at least three anti-terror drills over the past three weeks, aimed at beefing up their responsiveness and coordination under increasing terrorist threats.

The latest drill, which started at 9:30 p.m. on May 8, involved a police helicopter and more than 30 vehicles from SWAT units, traffic control and other emergency response departments, according to a spokesman with the Beijing Municipal Public Security Bureau.

The vehicles drove along the Fifth Ring Road, covering over 100 kilometers. The helicopter above sent images to a control center in real time, said the spokesman.

He said a series of similar exercises had been held in the capital to address the complex counter-terrorism situation facing Beijing.

On May 1, police conducted an anti-terror drill at the bustling Beijing Railway Station, a day after a terrorist attack claimed three lives and injured 79 others at a train station in Urumqi, capital of the far west Xinjiang Uygur Autonomous Region.

The police simulated a terror incident at the Beijing station. Without being informed of the drill, duty police officers at the station rushed to the site 50 seconds later. Other armed police forces, including SWAT and anti-terror teams, arrived within 15 minutes.

On April 25, Beijing police launched a drill to handle a simulated illegal gathering.

A knife attack at a railway station in the southern Chinese metropolis of Guangzhou injured six people on May 6. It was the third attack at a crowded train station in the country within 70 days.

On March 1, knife-wielding assailants killed 29 civilians and injured another 143 at a railway station in the southwestern Chinese city of Kunming.