Egyptian Civil Aviation Minister Mohamed Hossam Kemal said both black boxes of Russia's Kogalymavia flight 9268, which crashed in Egypt's northern Sinai region on Saturday, were recovered.

All commercial aircraft are obliged to carry two black boxes. One serves as a flight data recorder, while the other records sound in the cockpit, including the pilot's voice. Black boxes were introduced into civil aviation in the 1960s, and are built to withstand extreme conditions.

Kemal told a news conference that communication between the aircraft and air traffic control did not signal irregularities prior to the crash.

"The plane did not request a change of route," Kemal said, according to Reuters news agency. However, a senior air traffic control official earlier Friday said the pilot communicated that he was experiencing radio difficulties.

Egyptian Prime Minister Sherif Ismail defended Kemal's statement, saying there did not appear to be any unusual activity prior to the tragic incident.

An "Islamic State"-allied militant group based in northern Sinai claimed responsibility for the crash in a statement.

"The fighters of the Islamic State were able to down a Russian plane over Sinai province that was carrying over 220 Russian crusaders. They were all killed, thanks be to God," said the statement by the militant group, apparently referring to recent Russian airstrikes in Syria. Russian officials have dismissed those claims.

Tourism on the line?

Meanwhile, Egyptian Foreign Minister Sameh Shoukry warned "foreign" countries of speculation on the cause of the crash, saying there would be repercussions.

Countries should not take make measures based on speculations "that will impact the Egyptian economy and lead to damages. These nations must consider this as well as their relations with Egypt," Shoukry said in a statement.

A spokesperson for Egypt's tourism industry said it would be "premature" to comment on the possible impact the crash would have on the sector, considered an integral part of the Egyptian economy.

"It is too premature to detect the impact this will have on tourism. We need to know what happened first," Rasha Azazi, a tourism ministry spokeswoman, told AP news agency.

Around three million Russian tourists visited Egypt in 2014, comprising nearly a third of all foreign visitors last year.

Germany's Lufthansa, Air France and Emirates airlines announced that they would not be flying over Sinai until the circumstances of flight 9268 were clarified.

ls/bw (AFP, AP, Reuters, dpa)