Four Italians were kidnapped in the Libyan city of Mellitah, the foreign ministry said on Monday.The kidnapping took place near the city's ENI, the Italian oil giant, complex, the ministry added.The four worked for the Bonatti construction company, Xinhua reported.Foreign Minister Paolo Gentiloni said the country's crisis unit was working urgently on the case.Libya has been plagued by kidnappings and assassinations since the downfall of Muammar Gaddafi's government in 2011Italy closed its embassy in the north African country in February 2015 and urged its citizens to leave the country over the escalating violence.