The infrastructure suffered some damage during the war for independence with Ethiopia. Massawa, the principal port, serves Eritrea and northern Ethiopia. The port, which has a 7-m (24-ft) channel and pier facilities capable of accommodating five or six large vessels, was damaged by bombing raids from February 1990 to May 1991. In early 1992, agreements were concluded between the Eritrean and Ethiopian governments to make Assab a free port for Ethiopia, making Ethiopia dependent on Eritrean ports for its foreign trade. Assab has an oil refinery and facilities capable of handling more than one million tons of goods annually. As of 2002, Eritrea had 6 ships (1,000 GRT or over), totaling 19,100 GRT. Eritrea has 3,859 km (2,392 mi) of roads, of which 810 km (503 mi) are paved in 2002. A railway, which was almost completely destroyed during the war, once extended 317 km (197 mi) from Massawa on the Red Sea to Asmara, terminating near the Sudanese border. Reconstruction work on this railway starting from Massawa began in summer 1994 and is still underway. There were 21 airports and airfields in the country in 2001, only 4 of which had paved runways. The airport at Asmara (Yohannes IV) handles international jet transportation. In 1997, an estimated 174,000 passengers were carried on scheduled international and domestic flights. Repair of the railroad and highway network is necessary for the revival of agriculture and industry. The government of Eritrea has established a budget for transport rehabilitation, two-thirds of which is allocated for road repair to ensure that all parts of the country have access to modern roads.