IDF soldiers traveling near the Egyptian border fired into the neighboring country after thinking their bus had been shot at by terrorists, Wednesday morning.

It was not immediately clear if the bus was fired upon or if soldiers responded to hearing a nearby firefight.

The shooting, near Motzav Karmit, reportedly came as Egyptian security forces were engaged in a firefight with smugglers along the border.

Soldiers detained three Africans who had snuck into Israel, and hearing the gunbattle, responded by shooting toward the source of the fire. There were reportedly injuries on the Egyptian side, including an Egyptian policeman. The injuries were reportedly not from Israeli fire.

A bus carrying soldiers in the same area was fired upon from Egypt late last month.

On July 22, snipers in Egypt fired at an Israeli bus carrying troops along the Egyptian border near the Shivta army base. No injuries were reported in that incident, but the bus suffered some damage.

The border between Egypt and Israel has become increasingly volatile since the fall of former Egyptian president Hosni Mubarak’s regime last year.

The army recently reopened the road running along the Egyptian border after upping security measures.

In June, a man working on building a wall along the border was killed when a convoy of vehicles was ambushed in an attack combining rifle fire, antitank weapons and two explosive devices. Two terrorists who crossed into Israel were killed in an ensuing gunfight.

Six people were killed in August 2011 in a large coordinated terrorist attack near the border, causing the army to close the road for several months.

Israel is currently building a wall along the Egyptian border. Though originally planned to keep out African migrants sneaking into the country, it is increasingly being seen as a security measure as well.