At least 60 foreign hostages are still unaccounted for in the standoff with Islamic militants in Algeria, the country’s state news agency said Friday. Half the 132 foreign nationals have been freed, along with 573 Algerians, says Reuters. According to a Mauritanian news agency, the kidnappers offered to trade two American hostages for two jailed terrorists, including Sheik Omar Abdel-Rahman, the mastermind of the 1993 World Trade Center bombing. Some of the hostages were reportedly strapped to explosives, according to Garry Barlow, one of the freed hostages. British Prime Minister David Cameron said the British government had not been told by Algeria about the rescue mission beforehand.