KHARTOUM, Oct 30 (Reuters) - Sudanese military forces tightened security in the capital on Saturday ahead of planned nationwide protests to demand the restoration of a civilian-led government to put the country back on a path to democracy after a coup.

Thousands of Sudanese have already taken to the streets this week to protest against General Abdel Fattah al-Burhan ousting Prime Minister Abdalla Hamdok's cabinet in a takeover that led Western states to freeze hundreds of millions in aid.

In central Khartoum there was a heavy military deployment of armed troops that included the army and the paramilitary Rapid Support Forces.

Security forces had blocked roads leading to the defence ministry complex and the airport, as well as most of the bridges connecting Khartoum with its twin cities of Omdurman and Khartoum North.

With at least 11 protesters killed in clashes with security forces, opponents fear a full-blown crackdown.

"The army should go back to its barracks and give the leadership to Hamdok," said an activist who gave his name as Mohamed, who plans to protest. "Our demand is a civilian country, a democratic country, nothing less than that." 

In local neighbourhoods, protest groups blocked roads overnight with stones, bricks, tree branches and plastic pipes to try to prevent any attempts by security forces to enter.

In some streets there are makeshift barricades every 30-40 metres. “We will be on the streets to call for democracy,” said one activist who asked not to be named. 

A 75-year-old man who gave his name as Moatez and was walking the streets searching for bread said normal life had been brought to a complete halt in Khartoum. “Why did Burhan and the army put the country in this crisis? They could solve the problem without violence,” he said.

The United States, which is calling for the restoration of the civilian-led government, said how the army reacted would be a test of its intentions. 

Secretary of State Antony Blinken said Sudan’s security forces must respect human rights and any violence against peaceful demonstrators was "unacceptable".

The United States continues to stand with "Sudan’s people in their nonviolent struggle for democracy", he said on Twitter. 

The U.N. Special Representative in Sudan, Volker Perthes, said he remained in constant contact with all sides to facilitate a political solution.

'NO FEAR' 

With internet and phone lines restricted by the authorities, opponents of the coup have sought to mobilise for the protest using fliers, SMS messages, graffiti, and neighbourhood rallies.

Neighbourhood-based resistance committees, active since the uprising against deposed President Omar al-Bashir that began in December 2018, have been central to organising despite the arrests of key politicians. 

Bashir, who ran Sudan for nearly three decades, was forced out by the army following months of protests against his rule.

Khartoum committee activist Hussam Ibnauf he was confident of a big turnout. There was now "no fear factor", he said. 

Burhan has said he removed the cabinet to avert civil war after civilian politicians stoked hostility to the armed forces.

He says he is still committed to a democratic transition, including elections in July 2023. 

Hamdok, an economist, was initially held at Burhan's residence when soldiers rounded up the government on Monday, but was allowed to return home under guard on Tuesday.

The U.S. State Department official said he was, however, still under house arrest and unable to resume his work.

The U.S. official said tens of billions of dollars of debt relief sought by Sudan would not happen as long as the army was attempting to direct Sudan unilaterally.

The United States and the World Bank have already frozen assistance to Sudan, where an economic crisis has seen shortages of food and medicine and where nearly a third of the population are in need of urgent humanitarian support.

Several mediation efforts have emerged but there has been no sign of progress towards a compromise.