A Saudi Arabian student has been attacked on a bus in Dublin by a man who shouted “Allahu akbar” before saying he hated Muslims.

Mashael Khayyat, who is studying for a PhD in computer science at Trinity College, said she was on her way through the Irish capital on the number 70 bus to pick her two daughters up from school at the time.

“Suddenly an Irish man came to the bus with a bus pass, saw me wearing hijab (veil) and said Allahu Akbar to me,” which means “God is great”, she wrote on Facebook.

When Mrs Khayyat asked what the man meant, she said he told her Muslims “kill people”.

Mashael Khayyat is studying for a PhD in computer science at Trinity College Dublin (AFP/Getty)

“I said no, we do not kill people,” she wrote. “Then he hit me in my shoulder and said well ... I hate Muslims. I was shocked and frightened.”

Mrs Khayyat, 31, said she ran to the front of the bus, shaking, and told the bus driver what had happened. He alerted the police.

A spokesperson for the Garda Síochána (Irish police service) said officers were investigating the incident near Tara Street, adding: "A female alleges that she was assaulted by a male.

"Gardai arrived on the scene and spoke to both parties. The investigation is ongoing."

Mashael Khayyat lectured at Saudi Arabia's King Abdullah University before moving to Dublin for a PhD (AFP/Getty Images)

Mrs Khayyat, a former lecturer King Abdullah University, moved to Dublin from Jeddah with her husband and two children three years ago to complete a four-year scholarship from the Saudi Arabian government.

But she said the incident on 8 September has made her feel unsafe.

“I did not do anything to be treated badly like this, I am not hurting people with my hijab,” she wrote on Facebook.

“I went to my daughters with full of fear because I saw his anger and hate with no reason. I do not feel safe now.”

The mother urged Irish people to speak out against Islamophobia and hatred of any kind, saying she feared that “peaceful” Ireland could see a repeat of the killing of Saudi student Nahid Almanea in Essex last year.

A spokesperson for Dublin Bus, which operates the number 70, said police were contacted and officers removed a passenger from the bus.

"The safety of our customers and our employees is our primary priority and we take incidents of this nature very seriously," she added."