Children among dozens killed as gunmen ambush convoy of Egyptian Coptic Christians (GRAPHIC)

Gunmen opened fire on two buses and a truck carrying Coptic Christians in Minya, Egypt on Friday, killing at least 28, including children. Some 24 people were also injured in the attack.

The group of between eight and 10 gunmen, reportedly dressed in military uniforms according to eyewitnesses, approached the convoy in three four-wheel-drive pickup trucks before opening fire, according to local media reports and the Egyptian Interior Ministry.

"They used automatic weapons," Essam el-Bedaiwy, governor of Minya told state television as cited by AFP.

Heavily armed special forces and local police established a perimeter around the scene and launched a hunt for the attackers, setting up dozens of roadblocks in the area and sending out patrols to scour the desert road.

The Grand Imam of al-Azhar Ahmad al-Tayeb believes the attack was intended to destabilize the country. Al-Azhar is a center of Islamic learning in Egypt that dates back more than 1,000.

"I call on Egyptians to unite in the face of this brutal terrorism," al-Tayeb said while on a visit to Germany, as cited by Reuters.

The shooting, which occurred on the eve of Ramadan, happened as the victims travelled from Beni Suef province to the Coptic Orthodox Anba Samuel monastery near the southern city of Minya, 250km (155 miles) south of Cairo, according to local security sources, cited by Haaretz.

There is no immediate claim of responsibility. Egyptian President Abdel Fattah el-Sisi called an emergency meeting of security officials in the wake of Friday’s attack, Reuters reports.

Al-Bedaiwy confirmed the preliminary death toll, reports Reuters.

Ambulances dispatched from the cities of Beni Suef and Minya are transporting victims to local hospitals in Adwa, Minya, Maghagha, according to local news outlet Youm7.

The US Embassy in Cairo warned of an imminent but unspecified terrorist attack on the night of May 24.

“The Embassy is aware of a potential threat posted on a website by the Hassm Group, a known terrorist organization, suggesting some kind of unspecified action this evening,” the Egypt mission said in a statement.

The three-month state of emergency, declared in the wake of the Palm Sunday bombings in Tanta and Alexandria, is yet to expire.

On April 9, twin suicide bombs targeting Coptic Christians killed at least 44 people and injured more than 118  in Tanta and Alexandria. Islamic State (IS, formerly ISIS/ISIL) claimed responsibility for the attacks.

Coptic Christians make up roughly 10 percent of Egypt's population of 92 million and are the Middle East’s largest Christian community.

Pope Francis visited Egypt in April to show solidarity with Christians following the April attacks. He met Pope Tawadros II, the spiritual leader of the Coptics in Egypt.

In response to the Catholic Pope's visit, IS promised to escalate attacks in Egypt, warning Muslims to avoid Christian gatherings.

“The growing number of these terror attacks is not at all reassuring,” Fr. Rafic Greiche, the spokesman for the Egyptian Catholic Church, told local Egyptian media as cited by the AP.