At least 353 people were injured, one of them critically, when Egyptian security forces attacked a pro-Palestine demonstration outside the Israeli embassy in Cairo on Sunday night, according to witnesses and the Health Ministry.

Activists told Al Jazeera that army and internal security troops used tear gas, rubber-coated bullets and live ammunition to disperse thousands of protesters who had gathered to mark the 63rd anniversary of the "Nakba" or "catastrophe" – the day in 1948 that Israel declared its independence and thousands of Palestinians fled or were expelled form their homes.

At least two protesters were shot by live ammunition, while others were hospitalised after inhaling tear gas or being hit by rubber-coated steel bullets, some of which penetrated the skin, witnesses said.

One protester, Atef Yehia, was shot in the head, while another, Ali Khalaf, was shot in the abdomen. Both survived, though Yehia was being kept on a ventilator and would likely suffer brain damage, his friend said on Monday afternoon.

The crackdown on the protest also marked a setback for activists campaigning to limit the military’s judicial power in post-revolutionary Egypt. A senior police officer told Al Jazeera that 137 protesters had been arrested and would be questioned by a military prosecutor. As they awaited questioning, the protesters was being held in Hikestep military prison on the outskirts of Cairo, according to activists and a human-rights lawyer.

The violence began at around 11pm after a group of protesters surged toward the front of the multi-story office building that contains the Israeli embassy and managed to push aside some of the barriers that had been erected in front of the ground-floor entrance, witnesses said.

The crowd had called for Egypt to break off its diplomatic ties with Israel and for the Israeli flag to be taken down from the building.

Members of the Central Security Forces responded with a heavy volley of tear gas, driving the protesters back with support from military troops on the scene. Witnesses said the army forces – a mix of regular soldiers and military police – first fired in the air to disperse the protesters but then aimed at the crowd.

Protesters responded by burning tires in the street and throwing stones.

"The army was running after us, shooting rubber bullets," said Sanaa Seif, an activist who attended the protest. "I kept on hearing gunfire from everywhere, and someone told me that there was gunfire from the Central Security Forces … I wasn’t sure if it was rubber or live, people were saying rubber."

In the chaos, a friend of Seif’s, Youssef Bagato, was shot by a rubber-coated bullet that lodged in his back and had to be taken to a hospital.

Another protester had fainted nearby, and Seif and her friends helped him into the entrance of a building to recover. They found Khalaf suffering from a bullet wound below his stomach.

The group moved Khalaf inside a nearby shop to hide him from security forces but were forced to leave by the owner, who feared they would be found. They moved to a main street and put Khalaf into a cab with his friends to be taken to a hospital.

Yehia, who also had been hit during the initial retreat from the security forces, was taken first to the nearby Om el-Misreyeen Hospital and then to the more advanced Kasr el-Aini Hospital in central Cairo.

He had been struck by a single bullet above his right eye and was awaiting surgery on Monday afternoon, his friend, Sabry Khaled, told Al Jazeera. Doctors said he would likely suffer brain damage.

Yehia, who is in his early twenties, owns an Internet cafe and uses the income to support his three sisters and mother, Khaled said. His father died several years ago.

"He’s just like any other Egyptian who loves his country" and wanted to express his anger with Israel in a peaceful way, Khaled said.

Unclear Fate for Detainees

Street clashes continued for several hours after security forces dispersed the crowd, and at around 4am, Central Security Force and army troops closed in on the remaining protesters and arrested dozens.

Mohamed Effat, a freelance journalist, chronicled the arrests on Twitter.

"They pointed their guns at us, forced us to lie on our stomachs, fired heavily into air, cussing at and hitting us. An officer told me whoever looked up would be smacked on the neck," he wrote. "Last thing was that they took our phones and IDs, queuing us to put in [Central Security] cars while yelling ‘Have fun in military prison rev[olutionary] youth’."

Effat was released, but among those still detained were Tarek Shalaby and Mosaab Elshamy, two activists who had been prominent during the revolution.

Shalaby had activated the mobile phone livestreaming service Bambuser shortly before his arrest, leaving some video and audio of the incident posted online.

He had returned to Cairo at around 3am on Monday morning after an unsuccessful attempt to join a "Nakba Day" protest at the Rafah border crossing between Egypt and the Gaza Strip. The army shut down that demonstration, erecting several checkpoints along the road toward Rafah and preventing bus companies from ferrying protesters from Cairo.

In the wake of the revolution that unseated President Hosni Mubarak and replaced him with the Supreme Council of the Armed Forces, the army has exercised nearly complete power, and thousands of Egyptians – including at least hundreds of demonstrators – have been forced into military trials that many describe as lacking due process.

Mona Seif, an activist working against such trials, said that the arrests on Sunday night and Monday morning indicated that the armed forces were still exercising their sweeping law enforcement powers.

"I thought we had started to make some progress on this, as in they started to refer people to civil trials and not military trials, but apparently this is not true," said Seif, who is also Sanaa Seif’s sister. "A spokesman for the Suprme Council of the Armed Forces said a couple of days ago that anything that happens within the presence of the army is the army’s responsibility … and since they are basically everywhere, this is them telling us that whatever happens in this country, it will be referred to a military prosecutor."

Human rights lawyer Ragia Omran and relatives of the detained protesters traveled to Hikestep to visit the detainess and gather more information about them. As of Monday afternoon, it was unclear whether interrogations had begun or what charges might be filed.

"We had an idea before that the army and police aren’t very good," Khaled said. "But what happened last night and what happened to my friend made this idea concrete."
 
(Al Jazeera and agencies)