A Sudanese plane bombed Bentiu, capital of the oil-rich South Sudan border state of Unity, on Saturday, a local government spokesman said.
“Three bombs were released next to Bentiu Bridge, and at the moment one person is confirmed killed. But they did not break the bridge,” said Gideon Gatfan, spokesman of the Unity State government.
The bridge links Bentiu to a road leading to the border between Sudan and South Sudan some 60 kilometres (35 miles) to the north which has been the theatre of fierce clashes in recent days.
It was the second air raid reported by South Sudanese officials on Bentiu since Thursday.
The South Sudan army claimed Saturday to still be in control of the oil hub of Heglig after Khartoum said it had launched an offensive to recapture the area seized by Juba's forces on Thursday.
The clashes are the worst since South Sudan's independence from Sudan last July under a 2005 peace accord and have brought the two former foes the closest yet to a return to outright war.
No information was available early Saturday on the positions of the two armies.
Some two million people died in Sudan's 22-year civil war, one of Africa's longest, before the peace deal opened the way to South Sudan's independence.
When the South separated, Khartoum lost about 75 percent of its oil production and billions of dollars in revenue, leaving the Heglig area as its main producer. -Sapa-AFP