Venezuela has declared a state of emergency in a border region near Colombia after an attack by smugglers that left three soldiers and a civilian injured.

President Nicolas Maduro announced there will be 60 days of martial law in five municipalities in the north-western state of Tachira and closed the border until further notice.

"The constitution and the law give me the power to declare this state of exception for 60 days, extendable for 60 days," he said in a televised address.

"This decree provides ample power to civil and military authorities to restore peace."

"We've been discovering a frightful reality about how the criminals and paramilitaries operate. I'm under the obligation to free Venezuela of all this."

The 1,400-mile border has been plagued by violence and Mr Maduro added that an extra 1,500 soldiers had arrived to reinforce the area and prevent petrol and food smugglers from crossing.

Opponents immediately denounced the move as an attempt to distract attention from government failings and the deep economic crisis that has led to a collapse in support for Mr Maduro's socialist government.

As part of the crackdown against smugglers and traffickers, the government has already closed the border in Tachira at night, deployed thousands of soldiers and toughened jail sentences for smuggling.

There has also been a recent introduction of a fingerprint-scanning system to restrict the amount of any single product shoppers can buy.