Officer Leo Nyongesa said Sunday that the unidentified man was arrested overnight in the Kenyan town of Mandera in a security operation that also saw three other Somalis arrested.

Mandera has been tense after militiamen allied with Somalia's government drove al-Shabab militants out of the bordering town of Belet Hawo.

Nyongesa, the police head in Kenya's northeastern province said police are trying to verify whether the passport was fake.

More than 100 people fleeing from Somalia were arrested in Kenya in 2007 after Ethiopia sent its troops to the Horn of Africa nation to crush Islamist militants

By Abdifitah Ibrahim