Protests erupted in the northern Sinai city of el-Arish early Wednesday, hours after gunmen opened fire on three local security checkpoints and days after a similar attack in nearby Rafah claimed the lives of 16 soldiers.

Angry demonstrators rallied demanding protection from the state and shouting “God is great” in front of a governor’s office.

At least six people were wounded in Tuesday’s attacks on the checkpoints.

Shortly after midnight on Tuesday, Egyptian state news agency MENA reported that “unknown gunmen opened fire on a checkpoint on the main road between el-Arish and Rafah,” and that exchanges of gunfire continued late into the night.

The checkpoint described in the report was presumably the Al-Risa checkpoint, which had already been attacked 28 times since the fall of Egypt’s longtime leader Hosni Mubarak 18 months ago.

Egypt’s Al Ahram reported early Wednesday that the Al-Risa checkpoint and two other security installations in el-Arish had been attacked on Tuesday, and that one civilian had been shot in the crossfire. Other Egyptian media outlets did not initially report any injuries.

Local residents said the shooting subsided in the early hours of Wednesday morning.

The attacks came just two days after a deadly strike on a military installation in Rafah, in which terrorists killed 16 Egyptian soldiers and then charged, with armored vehicles, at the Kerem Shalom border checkpoint.

Many Egyptians blame Israel for Sunday’s attack and protesters on Monday night in Cairo called for the expulsion of the Israeli Ambassador Yaakov Amitai.

Egypt’s President Mohammed Morsi did not attend Tuesday’s funeral for the slain soldiers, possibly fearing some sort of backlash. He indicated, however, that his country would respect all of its existing international agreements, including the 1979 peace treaty with Israel, while defending its own interests.

Speaking to reporters who asked about the possibility of amending existing agreements with Israel, Morsi’s spokesperson Yasser Ali said that the president “stresses the country’s respect for international agreements.”

Ali added that it is still unclear who were the perpetrators of Sunday’s attack in Rafah. He said a joint task force involving several national agencies was working around the clock to investigate the incident.