Coptic Christians chant slogans during a protest following an attack on a bus carrying Christian pilgrims on their way to a remote desert monastery, in Minya, Egypt, Friday, Nov. 2, 2018.
Later on Friday, an IS-linked website reported that militants in Egypt with links to the group had claimed responsibility for the attack.
Since 2016, more than 80 people have been killed and 150 wounded in attacks on Coptic Christians in Egypt.
The local ISIS affiliate which spearheads militants fighting security forces in the Sinai Peninsula claimed responsibility for the attack in a statement.
The attackers then fled, a witness at the monastery said.
Assailants reportedly used side roads to reach the main highway and shoot at the buses, which were nearing the monastery.
Egypt's Coptic Christians, who make up about 10 percent of its population, have come under attack by Islamist radicals several times over the past years.
The spokesman for the Coptic Orthodox Church Boulis Halim had confirmed to Ahram Online that there had been seven fatalities and a number of injuries.
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At a memorial outside, the first lady placed a flower and the president laid a small stone on a marker for each of the victims. Other locals said they will survive this incident and be stronger because of it, but will never be the same.
On Saturday, el-Sissi is to open the World Youth Forum in the Sharm El Sheikh resort in Sinai, which has also seen deadly militant attacks.
Under heavy guard by masked security personnel on Saturday, hundreds of angry Copts gathered in and around Minya's Prince Tadros church from dawn for the funeral of six victims.
"This latest attack shows that the anti-ISIS (IS) campaign has not yet succeeded in Egypt, despite obvious efforts by the authorities to tackle it in different parts of the country", said H. A. Hellyer, senior non-resident fellow at the Atlantic Council and the Royal United Services Institute in London.
Friday's attack is the second to target pilgrims heading to the St. Samuel the Confessor monastery in as many years. Previous ones targeted churches packed with worshippers in Cairo, the Mediterranean city of Alexandria and Tanta in the Nile Delta north of the capital, leaving at least 100 people dead.
This follows attacks on dozens of churches, homes and businesses belonging to Copts after the bloody breaking up of two pro-Morsi gatherings in Cairo in August and with perceptions that Copts had backed his overthrow.
Copts have long complained of discrimination in Egypt and IS is not the only group to have launched sectarian attacks against the community.
The US State Department condemned the attack in a statement Friday.