NATO cut part of Yugoslavia's main motorway and bombed towns from the far north to south, stepping up the tempo of airstrikes as they entered their 56th day on May 18, Serbian media said.
Taking advantage of clearing weather, NATO planes blasted several fuel depots during the day on May 17 and then zeroed in on central and southern targets overnight.
In a raid on Nis, the third largest Serbian city and key industrial hub, missiles brought down the Trupalske Sume overpass of the motorway just north of town, state television (RTS) said.
The motorway crosses Yugoslavia's main republic, Serbia, and is the main overland trade and transport link between central and southeastern Europe.
NATO missiles and bombs have pummeled much of Yugoslavia's industry and infrastructure in a campaign to immobilize the Yugoslav military and reverse the mass expulsion of separatist-minded ethnic Albanians from Kosovo. The bombing began on March 24.
NATO has been striking increasingly at troops and tanks in Kosovo itself but has been less successful there because of its foe's skill at hiding forces in wooded, mountainous countryside, and timing military operations between rounds of air raids.
RTS and local Internet users reported other missile attacks early on May 18 around the southern towns of Leskovac, Vladicin Han, Vranje, and Prokuplje.
Vladicin Han residents were left without running water, while NATO targets in Vranje appeared to be a military barracks and a bridge over the Juzna Morava River, according to local media and Serbs filing information onto the Internet.
But the official Yugoslav news agency, Tanjug, said that attack caused heavy damage to Vranje's DIV tobacco factory building, the Nova Jugoslavija print shop, the Jedinstvo bus station, and residential buildings on three streets.
Vranje is in far southern Serbia close to the border of Macedonia but outside the province of Kosovo. The missile strike on Vladicin Han left residents without running water, Tanjug said.
Belgrade says some 1,200 civilians have been killed by NATO bombing. NATO admits that a few of its bombings have gone awry, killing and wounding innocents, but that civilian casualties are hard to avoid in a sustained bombing campaign.