At least four people were injured in a shooting late on Wednesday in San Antonio, a city in the US state of Texas, according to authorities.

The Fire Department of San Antonio said that four people were taken to the hospital after being shot outside a mall and two of whom were reported to be in critical condition.

It is still unclear whether it was a targeted shooting, police said.

The investigation into the incident was underway.

In November, Mexico government had said that it helped ten Mexican citizens to sue Walmart over the shooting at a store in the US border town of El Paso, Texas, that left eight Mexicans dead and eight others wounded.

Earlier in September, Walmart halted sales of ammunition for handguns and some military-style rifles.

The world’s biggest retailer, Arkansas-based Walmart has more than 4,700 stores across America, many in conservative regions where political opposition to gun control is strong.

Earlier in August, at least 20 people were killed and many injured in a mass shooting at the Walmart store in the US city of El Paso.

The massacre happened at a Walmart store near the Cielo Vista Mall, a few miles from the US-Mexico border.