The European Union ambassador to Sudan was attacked in his home in Khartoum on Monday, the bloc's top diplomat Josep Borrell said, as fighting between rival generals gripped the nation.
"A few hours ago, the EU Ambassador in Sudan was assaulted in his own residency," Borrell wrote on Twitter, without detailing any injuries to the envoy.
"Security of diplomatic premises and staff is a primary responsibility of Sudanese authorities and an obligation under international law," he added.
The European Union's ambassador to Sudan is 58-year-old Irish diplomat Aidan O'Hara. EU spokeswoman Nabila Massrali told AFP that he was "OK" following the assault.
"The security of the staff is our priority," she said. "The EU delegation has not been evacuated. Security measures are being assessed."
Ireland's deputy prime minister and foreign minister Micheal Martin said O'Hara was "not seriously hurt" but that the assault was "a gross violation of obligations to protect diplomats under the Vienna Convention".
"Aidan is an outstanding Irish and European diplomat who is serving the EU under the most difficult circumstances," Martin said.
"We thank him for his service and call for an urgent cessation of violence in Sudan, and resumption of dialogue."
The United Nations has called for an immediate ceasefire and international bodies, including the European Union, have expressed grave concern.
In a different incident a U.S. diplomatic convoy came under fire on Monday in Sudan, U.S. Secretary of State Antony Blinken said on Tuesday, adding that initial reports suggested that it was carried out by forces associated with Sudan's paramilitary Rapid Support Forces.
He said he spoke in separate phone conversations earlier on Tuesday to General Abdel Fattah al-Burhan, commander of the Sudanese Armed Forces, and General Mohamed Hamdan Dagalo, head of the RSF, and said that any danger posed to American diplomats was unacceptable.
Fighting between the Sudanese army and a rival paramilitary faction has killed around 200 people and wounded 1,800 after three days of urban warfare.