A student supporter of the Muslim Brotherhood and ousted Egyptian President Mohamed Mursi poses for a cell-phone photo by making the sign for "Rabaa," or "Four," in front of a burning car during a protest inside Cairo University, in Cairo, March 9, 2014. REUTERS/Mohamed Abd El Ghany

At least 15 Egyptian soldiers were killed at a checkpoint in Western Egypt, officials and state media reported. Al-Arabiya is reporting 31 soldiers dead.

In one of the deadliest attacks since Mohammed Morsi was ousted from power in June 2013, gunmen used rocket-propelled grenades and machine guns in the attack that occurred 320 miles from Cairo in El-Farafrah, which is near the Libyan border.

It is still unclear who launched the attack, but Reuters is referring to them as “smugglers” transporting weapons across the area. Reuters quoted one such “smuggler” as saying the price to transport weapons can go as high as 1 million Egyptian pounds ($140,000).

Weapons come in from militant groups on the Libyan border with Egypt and are transported to factions within the country, particularly to the Sinai Peninsula, security officials told Reuters. Since the Muslim Brotherhood was removed from power in Egypt, insurgents have amped up attacks on security forces, particularly in the Sinai, which borders Israel and Gaza.

Egyptian officials are increasingly worried conflict in Libya will spill over as militants attempt to create an Al Qaeda-style caliphate in Egypt.

"[Egyptian President Abdel-Fattah el-] Sisi came to us and asked us to stand behind the security forces and army to help them to control the border because what is happening in Libya poses a grave danger to Egypt," Mohamed al-Raghi, a tribal chief, told Reuters last week. Al-Raghi was refering to a secret trip Egypt’s president made to Libya to try to control the situation.

The official state news agency MENA reported 10 other soldiers were wounded.