An assailant stabbed an American man on Thursday while they were standing outside the U.S. Embassy in Cairo, security officials said.

The area around the U.S. Embassy has been the site of anti-American incidents and violence in the past, but stabbing attacks are uncommon despite political unrest that has roiled Egypt since the 2011 uprising.

Embassy spokesman David Ranz confirmed that a U.S. citizen was stabbed near the embassy, and said he was immediately rushed to the hospital. His condition was not known.

There were differing accounts of the attack.

An Egyptian official said the assailant, who was wielding a knife, attacked the American as he stood outside the embassy building, situated in the central Cairo neighborhood of Garden City.

The state-run daily Al Ahram said the victim, Christopher Stone, told prosecutors at a hospital that the attacker asked him his nationality and when learned he was American, pulled the knife and stabbed him.

Egypt's official news agency MENA reported that security authorities believe a brawl broke out between the American and the attacker over who was next in line.

The embassy was once heavily fortified, but security measures have been relaxed despite street protests during the past two years in nearby Tahrir Square, the focal point of the uprising that toppled longtime autocrat Hosni Mubarak.

The attacker was arrested and questioned by police, according to the security official.

A medic at the al-Qasr al-Aini hospital said the American was admitted to the emergency room, but declined to disclose further details.

Both officials spoke on condition of anonymity because they were not authorized to speak to the media.

Crime, including armed robberies, rape and assaults, has surged in Egypt in the past two years since the uprising. The country is awash with weapons smuggled across the border from Libya and elsewhere. Egypt's police force -- despised for its rampant rights abuses under Mubarak -- nearly collapsed amid the 18-day revolt and has since struggled to recover.

On Sept. 11, thousands of ultraconservative Salafis scaled the walls of the Embassy to rip apart the U.S. flag and replace it with an Islamic banner. The rally was prompted by a video made in the United States that ridiculed Islam's Prophet Muhammad.

The same night, Islamic militants attacked the U.S mission in the eastern city of Benghazi, Libya, killing U.S. Ambassador Chris Stevens and three other Americans there.

Months after the election of Egypt's Islamist President Mohammed Morsi, who hails from the Muslim Brotherhood group, the government has been criticized for failing to improve security and heal the economy.

At the same time, authorities are cracking down on rights activists and journalists.

Five rights activists went on trial Thursday in Cairo on charges of torching the campaign headquarters of a front-runner in last year's presidential election. Ahmed Shafiq, the former prime minister who lost the race to Morsi, had withdrawn his complaint against the five, but the state prosecutor proceeded with the case anyway. Among the five on trial were Alaa Abdel-Fatah, a well-known blogger and a youth leader behind the 2011 uprising, and his sister, Mona Seif, who has led a campaign against military tribunals over the courts' harsh and swift rulings.

Abdel-Fattah was detained for two months in 2011 over allegations he attacked soldiers carrying out a bloody military crackdown on protesters. He was later released without charges.

Also on Thursday, another Egyptian court ordered the release of 11 young men held on charges of belonging to the so-called "Black Bloc" group, which authorities have qualified as a terrorist organization. Members of the Black Bloc are masked protesters who surfaced last year during anti-Morsi rallies and vowed to defend other demonstrators from attacks by security forces or Islamist rivals. The 11 were detained during clashes between Brotherhood supporters and protesters during a mid-April rally in central Cairo. The court ordered their release because of lack of evidence.