Customs officials at Cairo International Airport prevented four foreign passengers from traveling yesterday. An airport official said that one of the four passengers was carrying a British passport, two passengers were carrying Swedish passports and one passenger was carrying a Belgian passport. The official said a passport officer suspected one passenger's passport and as a result all four passports were sent for technical examination at the criminal evidence department. Two passengers had legitimate passports, while the department found the Belgian and the Swiss passports to be forged. The four passengers are being held pending further investigation into their nationalities and method of entry into Egypt.