The Sudan People's Liberation Movement-North (SPLM-N) said they were just a few kilometres from El Kurmuk, the major town in southeastern Blue Nile state.
"It's very close and we are controlling the Kurmuk airstrip," which is west of the town, rebel spokesman Arnu Ngutulu Lodi told AFP.
"This is a very serious one," he said of the battle.
The army denied there was fighting on the outskirts of Kurmuk but said its forces had withdrawn from an area southwest of the town which, two days earlier, it announced it had "liberated."
The United States said on Friday it was "deeply concerned" by reports of clashes between Sudan and South Sudan in disputed border areas between Blue Nile and South Sudan's Upper Nile state.
Khartoum accuses South Sudan of backing rebels in South Kordofan and Blue Nile, but the South denies such support.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
