By Ali Abdelaty

CAIRO, April 19 (Reuters) - Egyptian security forces have tracked down and killed a gunman suspected of involvement in an attack near St Catherine's Monastery in southern Sinai that left one police officer dead and three wounded, the Interior Ministry said on Wednesday.

Islamic State claimed responsibility for Tuesday's attack on a police checkpoint about 800 metres (yards) from the monastery, one of the world's most important Christian sites.

Security forces and local Bedouins followed the attackers' escape route and killed the suspect in a shoot-out. Police found an automatic weapon and ammunition, the ministry said.

Tuesday's attack came 10 days before Pope Francis is scheduled to visit Egypt and just over a week after two deadly suicide bombings on Christian churches, also claimed by Islamic State, killed 45 people.

St. Catherine's, founded in the sixth century and located at the foot of Mount Sinai, is one of the oldest Christian monasteries in the world and a UNESCO world heritage site. It is part of the Eastern Orthodox church.

Egypt's Christian minority, which makes up about 10 percent of the country's 92 million people, has increasingly been targeted by Islamist militants, with three deadly church attacks in the span of four months.

Egypt has for years been battling an Islamist insurgency in northern Sinai, which gained pace after the military overthrew President Mohamed Mursi of the Muslim Brotherhood in 2013 following mass protests against his rule.

(Reporting by Ali Abdelaty and Arwa Gaballa; Writing by Giles Elgood; Editing by Alison Williams) ((eric.knecht@thomsonreuters.com; +20 2 2394 8102; Reuters Messaging: eric.knecht.thomsonreuters.com@reuters.net))