Egypt has referred 12 men to military trial for alleged involvement in a cell behind a narrowly averted attack on tourists at a pharaonic temple in June, prosecutors said Thursday.

The assailants had been recruited by the Islamic State group's Egyptian affiliate, along with two "foreigners" who were killed in the incident at the Karnak temple in Luxor, the prosecution said in a statement.

Egyptian police were closely monitoring Friday the condition of the third assailant in a foiled suicide attack on Luxor's Karnak temple, who is critically wounded in hospital, officials said.

They were also hunting for three people suspected of aiding Wednesday's failed attack, a police official in Luxor said, after security services said they had narrowly averted a "massacre" of tourists at the popular ancient site.

Egyptian prosecutors contradicted Thursday police claims they had foiled a suicide and gun attack at the ancient Karnak temple by preventing assailants from entering the site.

Police said Wednesday the attempted attack was foiled after policemen asked to search bags in the trunk of a taxi trying to enter the site in Luxor and discovered a cache of weapons.

A foiled attack on one of Egypt's most popular ancient attractions was raising fears Thursday for tourism and foreign investment as the country tries to recover from years of political and economic chaos.

Bombings and militant attacks have been common since the army ousted president Mohamed Morsi in 2013, targeting security forces in retaliation for bloody repression of the Islamist's supporters.

Police said they foiled an attempted suicide bombing Wednesday on one of Egypt's most popular ancient attractions in Luxor, in a rare assault on the country's vital tourism sector.

Egypt has been shaken by a tide of attacks claimed by jihadists since the army toppled the democratically elected government two years ago. 

Nineteen people were killed and 15 injured when two minibuses plunged into an irrigation canal in southern Egypt early on Tuesday, a health ministry official said.

An Egyptian army MiG-21 aircraft crashed Sunday near the southern city of Luxor, leaving one person dead and three others injured on the ground after the crew ejected, officials said.

The Russian-built MiG was conducting a routine training flight when it caught fire shortly after takeoff from a military airport in Luxor.

Hot air balloon flights resumed in the city of Luxor on Sunday, nearly two months after a deadly accident killed 19 tourists, Egyptian officials told Agence France Presse

Four flights took off from the ancient temple city, with around 70 tourists on board, said Ahmed Abboud who heads the Balloon Flights union.

An initial probe into a hot air balloon crash that killed up to 19 tourists in Egypt has ruled out any criminal activity as a cause of the accident, the official MENA news agency reported on Wednesday.

"Investigations so far by the general prosecution show no suspicion of criminal activity," MENA said, citing the preliminary findings of the investigation into Tuesday's accident at the Egyptian temple city of Luxor.

A hot air balloon exploded and plunged to earth at Egypt's ancient temple city of Luxor during a sunrise flight on Tuesday, killing up to 19 tourists, including Asians and Europeans, sources said.

The balloon carrying 21 tourists from Hong Kong, Japan, France, Britain and Hungary was flying at 300 meters (1,000 feet) when it exploded and caught fire, a security official said.