Thousands of Sudanese protesters were camped outside army headquarters for a fifth day on Wednesday demanding President Omar al-Bashir step down, after the police ordered their forces not to intervene. In what has become the biggest challenge yet to Bashirs three decades of iron-fisted rule, crowds of demonstrators thronged the sprawling complex through the night, singing and dancing to the tunes of revolutionary songs, witnesses said. Hundreds of mobile phones were held aloft, shining a sea of lights on the tide of people massed outside the buildings. "The night passed peacefully without any incident," said one protester who spent the entire night at the complex. "We believe that the support from the soldiers on the ground and now the police is definitely growing." However, Bashir loyalists have called for a support rally for the president on Thursday, and urged all members of the ruling party to take part. "The National Congress Partys executive bureau supports the national dialogue partners initiative to organize a gathering to be seen by all the people on Thursday," the acting chief of Bashirs ruling party, Ahmed Harun, said in a statement. "I call on all members of NCP across the state of Khartoum to participate in this rally." The anti-government demonstrators have braved regular volleys of tear gas from members of the powerful National Intelligence and Security Service since they began camping at the army headquarters on April 6, protest organizers say. But for the first time overnight Tuesday they did not face any "threat" from security agents during the night, said the protester who did not want to be named for security reasons. "The soldiers at the complex are also angry after the attacks of tear gas and are determined to prevent them," another demonstrator told AFP. Witnesses said the troops had stationed several vehicles loaded with machine-guns at the gates of the complex, which also houses Bashirs residence and the defence ministry. On Tuesday, security agents had to abort bids to disperse the crowds when soldiers fired in the air to counter incoming volleys of tear gas from security agents. "It seems the police too are now with us," said the protester. "When we were coming to the army building last night we saw many policemen but they did not stop us." The police on Tuesday ordered its officers on Tuesday to avoid intervening against the demonstrators. "We call on God to preserve the security and calm of our country ... and to unite the Sudanese people... for an agreement which would support the peaceful transition of power," a police spokesman said in a statement. On Wednesday, protesters were raising funds to ensure a regular supply of food and water for the crowd. "Many shop owners and businessmen have offered us free supplies," said another demonstrator. Protest organizers launched their latest campaign on Saturday as part of a months-long movement against Bashirs 30-year rule. Demonstrations first erupted on December 19 in response to a government decision to triple the price of bread. But they quickly mushroomed into a nationwide campaign against Bashirs rule with rallies held across cities, towns, and villages. Bashir has remained defiant, and imposed a slew of tough measures including a nationwide state of emergency, which has led to scores of arrests or journalists and activists. Officials say 38 people have died in protest-related violence so far. On Tuesday, the United States, Britain, and Norway for the first time threw their weight behind the protesters, calling for a credible political transition plan in Sudan. "The time has come for the Sudanese authorities to respond to these popular demands in a serious" way, the so-called troika of Western diplomatic players said. "The Sudanese authorities must now respond and deliver a credible plan for this political transition." Defence Minister General Awad Ibnouf has vowed the army would prevent any slide into chaos. "Sudans armed forces understand the reasons for the demonstrations and is not against the demands and aspirations of the citizens, but it will not allow the country to fall into chaos," Ibnouf said on Monday, according to state media. The umbrella group spearheading the protests has meanwhile appealed to the army for talks on forming a transitional government.