AMMAN, Aug 20 (Reuters) - Three Lebanese soldiers were killed and one was critically wounded on Sunday when their armoured vehicle hit a landmine in an area along the Lebanese-Syrian border, a security source said.

The area where the soldiers were killed was near a border stronghold near where Shi'ite Muslim Hezbollah militia recently forced Sunni Muslim Syrian militants to leave in a joint cross-border operation with the Syrian army, the source added.

(Reporting by Suleiman Al-Khalidi; Editing by David Goodman) ((suleiman.al-khalidi@thomsonreuters.com; +962 79 5521407; Reuters Messaging: suleiman.al-khalidi.reuters.com@thomsonreuters.net))