CAIRO — At least two people were killed on Sunday when a stray rocket hit their house as rival Libyan militias exchanged heavy fire around Tripoli's international airport, a security official said. The weeklong battle over the airport is being waged by a powerful militia from the western city of Zintan, which controls the facility, and Islamist-led militias, including fighters from Misrata, to the east of Tripoli. The bombardment resumed early Sunday after cease-fire efforts failed, the official said on condition of anonymity because he was not authorized to speak to media. A Libyan Arab Airlines plane was hit by a mortar shell and a column of black smoke could be seen billowing from inside the airport, which has been closed since Monday. Tripoli is witnessing one of its worst spasms of violence since the ouster of longtime dictator Muammar Gaddafi in 2011. The rival militias, made up largely of former rebels, have forced a weeklong closure of gas stations and government offices. In recent days armed men have attacked vehicles carrying money from the Central Bank to local banks, forcing their closure. The Central Bank had said banks would reopen on Sunday, but they remained closed as the fighting resumed. Renegade Gen. Khalifa Hifter, who is waging his own offensive against Islamic militants in the eastern city of Benghazi, denounced what he called an attempt by “remnants and agents of terrorism” to destroy Tripoli's airport and terrorize the people. Hifter, who appeared on Libyan TV Saturday, said “our troops in Tripoli have bravely confronted the aggressive militia attacks” and vowed that the “coming few days will be decisive with the escalation of our military operations.” In Benghazi, Libya's second largest city, gunmen assassinated an army officer late Saturday while he was driving home in his car, and early Sunday a former special forces officer was shot dead in the downtown Salmani district, according to a local security official. The official spoke on condition of anonymity because he was not authorized to brief reporters. The United Nations Support Mission in Libya said last week it was temporarily withdrawing its staff because of the deteriorating security situation. – AP