Libya said a Sudanese military transport plane bound for a Tripoli airport under control of an armed faction had entered its airspace to supply a "terrorist group" with ammunition, a government statement said on Saturday.
Sudan confirmed it had sent a military plane but said it had only carried equipment for a joint Libyan-Sudanese state border force.
Libya is in turmoil three years after the ousting of Muammar Qadhafi as armed groups, partly linked to Islamists, have seized the capital Tripoli and set up an alternative parliament and government.
"This work from the Sudanese state violates (the sovereignty) of the State of Libya and interferes with its affairs," the Libyan statement said, adding that Libya had asked the Sudanese military attache to leave the country.
"Sudan is interfering by supporting a terrorist group," it added.
Libya said the Sudanese plane had been bound for Tripoli-Matiga airport and made a refuelling stop in the Libyan desert oasis Kufra near the border to Sudan. Ammunition had been found loaded on that plane during an inspection at Kufra airport, it added, without saying whether the plane was still in Kufra.
Matiga is a military airport now used mainly for commercial flights after Tripoli's main international airport was damaged by fighting between rival armed groups. Matiga is under control of an alliance of factions challenging the government which has relocated to Tobruk in the far east to escape the violence.
"We, the Libyan government, firmly denounce that a Sudanese military plane has penetrated the Libyan airspace without an official permit from the Libyan government. The plane was carrying ammunition which had not been officially approved by the Libyan government," the statement said.
But Sudan, led by an Islamist government, described the incident as misunderstanding, saying the plane had carried equipment for a joint Sudanese-Libyan border force to tackle smuggling and human trafficking.
"The plane did not carry any material for armed groups in Libya," Sudan's army spokesman al-Sawarmi Khalid told the local TV channel Shouruq. The Sudanese army was not interfering in Libya, adding that Libyans were able to overcome the current crisis without any outside intervention, it said.
ÙŽQadhafi used to fund and supply rebels in the western Sudanese region of Darfur but bilateral relations have improved much since his overthrow.
Sudan, like other neighbours, has trained Libyan soldiers and officers as part of international efforts to build up an army and police force. Khartoum also participates in conferences of Libya's neighbours discussing support to stabilise the oil producer.
South Sudan has accused its arch-rival Sudan in the past of arming rebels operating on its territory, a claim denied by Khartoum which has accused Juba of supporting Sudanese rebels with weapons.
