About 10 foreigners are missing after an attack on a Libyan oil field, and it is possible they have been taken hostage, the Czech Republic's foreign minister said Saturday. Foreign Minister Lubomir Zaoralek said the workers who were missing from the Ghani oil field included one from the Czech Republic, one from Austria and others from Bangladesh and the Philippines. "We are examining the possibility that a kidnapping has taken place," Mr. Zaoralek said. Libya's oil security forces said Friday that they had retaken control of the oil field after militants attacked it, killing seven guards. Mr. Zaoralek said there had been no contact from any group claiming responsibility. He added that the Foreign Ministry was convinced that the Czech citizen had not been killed in the attack. Libya's state oil company said that at least seven foreigners, who also included a citizen of an African country, were missing. "Foreigners from an Austrian oil services company operating in the field are still missing since the time of the attack," said a National Oil Corporation spokesman, Mohamed el-Hariri. "We do not know their fate." In Vienna, a Foreign Ministry spokesman said that a 39-year-old Austrian working for an oil field management company was among the missing. Four years after the ouster of Col. Muammar el-Qaddafi, Libya is caught up in a conflict between two rival governments and their armed forces, who are fighting to control the country's oil wealth. The chaos has allowed militants from the Islamic State and Ansar al-Shariah to gain a foothold in the country.