CAIRO, May 27 (Xinhua) -- Islamic State (IS) announced on Saturday that its fighters conducted a shooting that killed at least 29 Egyptian Christians on Friday, a statement of the group reported.

"A security detachment from Caliphate soldiers has killed dozens of Christians and burnt out their buses," said the statement posted on Telegram, an encrypted instant messaging system used by the IS to communicate with its followers.

The statement which has been published by the IS-affiliated Aamaq news agency said the attack left 32 killed.

On Friday, masked gunmen in three four-wheel-drive vehicles attacked two buses and a truck carrying Coptic Christians on a visit to a monastery south of the Egyptian capital, killing at least 29 people, including children, according to the health ministry's latest update.

About 70 Coptic Christians, who make up about 10 percent of Egypt's population of 92 million, have been killed in bomb attacks on churches in the cities of Cairo, Alexandria and Tanta since December.

Those attacks were claimed by the IS.

Egyptian air forces carried out six air strikes against jihadist training camp on Friday in retaliation for the Minya bus attack.

In a televised address to Egypt's people, President Abdel Fattah al-Sisi said "Egypt will not hesitate in striking terror camps anywhere, either inside (the country) or outside it."

On Saturday, a statement of the armed forces said that the Egyptian military is continuing to carry out air strikes against militant training camps outside the country.

"The air forces completely destroyed the targeted training camps and bases of the terrorists who carried out the attack against the Christians in Minya," the statement added.

The air eagles returned home while the armed forces continue in their operation to maintain the security of the country, added the armed force spokesperson.