A drill for joint patrols and law enforcement action on the Mekong River was carried out by police from China, Laos, Myanmar and Thailand on Tuesday to improve their capabilities in dealing with emergencies, cracking down on cross-border crimes and maintaining security along the river, authorities said.

It was one of the activities marking the 10th anniversary of the joint program this year.

At 2:30 pm, three red signal flares rose into the sky, and police from the four countries headed to their designated stretches of water. The Chinese police rehearsed arrests, rescues and clearing underwater obstacles.

From January through November, police from the four countries cracked 2,513 cross-border criminal cases, seized 12 metric tons of drugs and arrested 2,064 drug-related suspects, along with 2,626 suspects involving in illegal immigration and cybercrimes, the Yunnan provincial public security department said.