South Korean cargo transportation suffered no serious disruption Thursday despite a strike by unionized truck drivers, who are demanding the reinstatement of fired workers, according to Yonhap News Agency.

The Korean Cargo Workers' Union, which claims about 15,000 members, launched a nationwide strike earlier in the day after talks with their top client, Korea Express Co., broke down.

"As of now, there are no disruptions at major ports, but the unionized cargo drivers are expected to block traffic coming in and out of ports and container holding yards," an official at the Ministry of Land, Transport and Maritime Affairs was quoted as saying. "We have already warned that appropriate measures will be taken," he said.

Cargo container trailer traffic in the Busan port, the country's largest, and other major ports were running without disruptions, but some inland container depots like Uiwang and Yangsan are adversely affected to some degree.

According to the ministry, there are 21,400 container trailer trucks across the country, about 4,000 of which are run by unionized workers.

"In emergency steps, military trucks will be mobilized and more cargo rail services are scheduled to prevent the possible delay in shipments during the strike," the official said, adding that the strike has no justification.