NAIROBI, Kenya - Kenyan police have detained a man holding a Canadian passport who is suspected of having ties to a radical Islamist group that ruled Somalia for the past six months until it was overthrown last week by Ethiopian-backed transitional government troops.

The man, whose identity is unknown, was being held by police in northern Kenya after he and seven others carrying Eritrean passports were caught trying to cross into Kenya on Monday. Members of Somalia's Union of Islamic Courts (UIC) have been fleeing south toward the Kenyan border since the Ethiopian-backed government troops seized the capital, Mogadishu, last week.

"It's difficult to judge if they are Islamic Courts fighters, but a number of them were Eritrean and one had a Canadian passport,'' said Kenya police spokesman Gideon Kibunja. Eritrea has been accused of sending arms and fighters to the UIC, a charge it denies.

Kibunja said the men had claimed refugee status, but tensions over a UIC incursion have increased vigilance.

The UIC dramatically rose to power six months ago, seizing towns and cities across the Horn of Africa country. Their leader, Sheikh Hassan Dahir Aweys, is on a U.S. and UN terrorist list for his alleged ties to al-Qaida. They sought to rule Somalia with a strict interpretation of Qur'anic law, punishing criminals with floggings and executions.

The Canadian High Commission in the Kenyan capital Nairobi said it was attempting to get information about the Canadian detainee, but as of yet was unclear on details.

"Consular officials are aware of the arrest on the Kenya-Somalia border. We are actively investigating whether Canadian nationals were detained in order to provide them with consular help,'' said Ian McKinley, a counsellor with the High Commission.

McKinley said Canadian officials were investigating whether the man's passport was authentic. He said they had not yet spoken to the man and were having a hard time getting information from Kenyan officials.

Canada has a travel warning on Somalia, advising citizens not to travel there, or if there to leave the country immediately. McKinley said the detained Canadian may have been heeding the government's advice.

The eight detainees were being interrogated by Kenyan police in the northern town of Garissa.

Ethiopia declared war on the Islamists on Dec. 24, sending in fighter jets and tanks to boost the government's troops. The Islamists retreated south, ushering in a border reinforcement by Kenyan troops.

Somali refugees have been spilling over the Kenyan border since the country was plunged into anarchy in 1991, beginning a 15-year civil war that was finally brought to some conclusion when the Islamists took power. However, the past year has seen an increase in renewed tension between the UIC and the government.