The tension in the Sinai Peninsula continued on Saturday night, as a group of armed men opened fire at peacekeeping troops near the border with Israel.

A security source in Sinai told Reuters that the attack “happened in Um Shyhan area in the middle of Sinai but no one got injured.”

The incident came just days after the start of a military operation in the area against terrorists suspected of being behind last Sunday’s attack on Egyptian border guards which killed 16 people.

The same security source told Reuters that a group of armed men had earlier clashed with Egyptian security forces near the scene of the latest attack after they opened fire at a police checkpoint. No one was injured.

Police checkpoints have come under a series of similar attacks by armed assailants since last Wednesday.

On Friday, witnesses reported that several army tanks were heading towards the town of al-Arish, the main administrative center in North Sinai. A day earlier, residents of al-Arish reported that the Egyptian military had sent reinforcements of “unprecedented” size into the peninsula. The forces reportedly include 60 tanks on 30 tank-transporters, 12 armored personnel carriers, 15 additional armored vehicles, more than 20 armored jeeps and 10 Military Police jeeps.

The Israeli Cabinet voted on Thursday to approve an Egyptian request to send in helicopters to the Sinai Peninsula. The approval was given for a period of several days and allows five aircraft to enter the region. The move is designed to assist Egypt in its military operation against terrorist elements in the Sinai.

Under the peace agreements signed between Israel and Egypt in 1979, the Sinai Peninsula is to be a demilitarized zone and Israeli approval is required for Egypt to send in military forces to the region.

Also on Friday, the Egyptian army captured six people it regards as “terrorists” in the Sinai.