Two suspected drug traffickers were charged last night after police seized $73 million worth of heroin in one of the territory's biggest hauls of the drug. Police said they made the arrests after the men rammed their vehicle into another car as they tried to escape officers in Sheung Shui. The two suspects, aged 40 and 46, arrived in a car at the Landmark North car park in Lung Sum Avenue on Thursday evening, as about 30 officers from the Narcotics Bureau waited for them. The suspects approached another vehicle in the car park and allegedly unloaded four bags containing 70kg of heroin into their own vehicle, police said. The men drove off with police giving chase but were overpowered after their car rammed into another. Officers seized four bags containing high-grade heroin hidden in the car boot. Narcotics Bureau head Chief Superintendent Henrique Koo Sii-hong said the drug had come from the Golden Triangle and had been transported via Guangdong. He estimated its street value at $73 million. The pair were last night jointly charged with trafficking in dangerous drugs and will appear at Fanling Court today. Mr Koo said about 1,300kg of heroin - four times the amount seized by police and Customs - finds its way into Hong Kong every year. He said government figures indicated there were between 16,000 and 17,000 drug addicts. 'We estimate about 10,000 drug addicts are on heroin, excluding those who attend methadone centres,' he said. 'Each addict takes about a gram [of low-purity heroin] a day and about 1,300kg of heroin is required in Hong Kong a year.' The amount of heroin seized by police and Customs rose from 209kg in 1998 to 287kg last year.