Five people have been arrested for their alleged involvement in a mob attack on Shia Muslims in Egypt's Giza governorate.

Four Egyptian Shias were killed and several injured in the attack in Zawyat Abu Musalam village on Sunday, an incident which has heightened fears of sectarianism in Egypt.

The mob gathered outside a house where the Shias were sheltering. They then beat them and set the house on fire. The attack was captured on video and went viral on the internet.

Giza prosecutors on Monday ordered the arrest of 15 people implicated in the murders.

The funeral of those killed in the attack took place at Al-Sayeda Nafisa Mosque in Cairo on Monday

Leftist lawyer and former presidential candidate Khaled Ali was among a number of activists who attended the funeral.

The murders have been denounced from across the political and religious spectrum.

Egypt's ultraconservative Salafists have been accused of fuelling anti-Shia sentiment which led to the attack.

Egyptian Shia leaders are expected to hold a press conference on the murder on Wednesday, said Behaa Anwar, spokesperson of Egypt's Shia community and head of the Misr El-Fatimiya Human Rights Centre.

One of those killed was a local Shia leader, Hassan Shehata, officials said.

Anwar vowed to secure justice for the victims of the "heinous massacre."

There is no official tally of Shia Muslims in Egypt but analysts put the number at between 500,000 and one million.