Chinese security firms showcased their latest high-tech tools this week at Latin America's largest security trade show, and walked away with several top prizes.

The three-day Expo Seguridad Mexico, which closed Thursday in Mexico City, featured more than 30 Chinese firms displaying devices from high-definition surveillance systems to giant x-ray scanners that can detect weapons or contraband being shipped inside tractor trailers.

"China is modernizing its manufacturing," Ray Wang, a representative of the Beijing-based Nuctech company, told Xinhua during the opening Tuesday. "We don't just make shoes anymore. Now we sell high technology around the globe."

The technology Wang's company has developed since 1997 to inspect containers and trailers with x-ray scanners has made it the world leader in its field for the past three years, with a 25 percent share of the global market and a presence in 142 countries.

"We began to export to this (Latin American) market two years ago, and today we have a subsidiary in Mexico," Wang said.

Across the aisle from where Wang and his colleagues met with potential clients, Chinese firm Dahua Technology presented its state-of-the-art video surveillance cameras.

"Our strength is HD-CVI technology, which we patented," Dahua's marketing manager Angela Lu said.

High Definition Composite Video Interface, or HD-CVI, offers a new way to transmit video signals -- over coaxial cables instead of the traditional analog method -- to provide higher definition images, up to 450 percent better resolution than standard CCTV, at an affordable price.

The "100-percent Chinese company" has the world's second-largest market share in security equipment manufacturing, according to its website, and its devices help protect sites as varied as the London Underground, a UNESCO-designated site in Italy, and China's Three Gorges Hydropower Plant.

"Expo Seguridad is important for us, so Mexicans can get to know our technology," said Lu.

Dahua was voted "Best Manufacturer" at the expo, winning this year's top Mexico Excellence Award, which was also awarded in the categories of "Best Distributor," "Best Integrator," and "Most Socially Responsible."

Among the Chinese firms at the expo was China North Industries Corporation (Norinco), the largest manufacturer of armored vehicles for China's armed forces and police departments.

According to one Norinco representative, several models the company made for the security forces of more than 30 countries were rewarded prizes by their governments.

Some 350 security companies from Mexico and around the world took part in this year's 14th edition of the annual trade show, which was expected to draw some 17,000 visitors to Mexico City's Centro Banamex exposition center.

One attendee noted there were more Chinese companies at the expo than ever before.

"We are looking for distributors and representatives that we can work with here in Mexico," a representative of Beijing Landwell Electron Technology said.

Founded in 1998, the company makes long distance RFID (radio-frequency identification) equipment for guards and security personnel.

Landwell has entered the European and South American markets, and hopes to soon break into Mexico's.

Last year's expo drew nearly 14,500 visitors, mainly from Mexico. Of the more than 400 visitors from other countries, most came from the United States, followed by Colombia, Guatemala, Panama and Peru, but also from Canada, Spain, France and Italy.

According to a report on the expo, the vast majority of potential clients were interested in CCTV solutions, followed by intrusion alarms, IP (internet protocol) cameras for surveillance, biometrics, fire alarms and GPS vehicle tracking systems.