BEIJING, June 21 -- Over the first half of this year, Chinese authorities have confiscated 4.74 tonnes of drugs of various kinds in their anti-narcotics enforcement at border ports, arresting 528 criminal suspects, according to an official statement Wednesday.

The National Immigration Administration (NIA) said in the statement that as of Tuesday, relevant operations had solved 361 border cases, among which there were 102 drugs weighing more than 10,000 grams in each case.

A total of 528 suspects of drug-related crimes have been arrested, and the law enforcers have also dealt with 192 individual drug dealers, the statement said, adding that 31 transnational or interprovincial drug-trafficking rings have been busted.

The authorities also confiscated more than 703 tonnes of materials for drug manufacturing.

These operations have effectively curbed the cross-border transport of drugs and relevant materials to and from the country, according to the statement.

The statement said the NIA will further implement arrangements for an anti-drug special campaign, strengthen control at border ports, intensify the investigation of relevant violations, target drug-trafficking rings and networks as well as their leaders, and enhance law enforcement cooperation among different countries and regions.