This file photo shows South Sudan People's Defense Forces (SSPDF) troops at the Rajap Police Academy in Juba, capital of South Sudan, April 26, 2019.(Photo: Xinhua)

Sudan's military seized power from a transitional government on Monday and a health ministry official said seven people were killed by gunfire and 140 injured in clashes between soldiers and street protesters.

The leader of the takeover, General Abdel Fattah al-Burhan, dissolved the military-civilian Sovereign Council that had been established to guide the country to democracy following the overthrow of long-ruling Omar al-Bashir in a popular uprising two years ago.

Burhan announced a state of emergency, saying the armed forces needed to protect safety and security. He promised to hold elections in July 2023 and hand over to an elected civilian government then.

"What the country is going through now is a real threat and danger to the dreams of the youth and the hopes of the nation," he said.

The Sudan information ministry, which is still loyal to ousted prime minister Abdalla Hamdok, said on its Facebook page that the transitional constitution gives only the prime minister the right to declare a state of emergency and that the military's actions are a crime. Hamdok is still the legitimate transitional authority, it said.

The UN Security Council was likely to discuss Sudan behind closed doors on Tuesday, diplomats said.

White House spokesperson Karine Jean-Pierre said: "We reject the actions by the military and call for the immediate release of the prime minister and others who have been placed under house arrest."

Youths opposed to the coup barricaded streets and clashed with troops. The main opposition coalition, Forces of Freedom and Change, which pushed for Bashir's removal and negotiated the military-civilian council, said on Twitter it was calling for peaceful actions in the streets to overthrow the military takeover, including demonstrations, the blocking of streets and civil disobedience.

Hamdok, an economist and former senior UN official, was detained and taken to an undisclosed location after refusing to issue a statement in support of the takeover, the information ministry said.

The ministry urged resistance and said tens of thousands of people opposed to the takeover had taken to the streets and had faced gunfire near the military headquarters in Khartoum. Central bank employees announced a strike to reject the coup, the ministry said.

Troops had arrested civilian members of the Sovereign Council and government figures, the ministry said. 

Also detained was the news director of state TV, his family said.

The US State Department said Washington had nothing to share on Hamdok's whereabouts and condition. A department spokesman said it was pausing $700 million in economic support for Sudan.

In Khartoum's twin city Omdurman, protesters barricaded streets and chanted in support of civilian rule.

"Burhan cannot deceive us. This is a military coup," said a young man who gave his name as Saleh.