KHARTOUM, Oct 18 (Reuters) - A sit-in calling on the military to dissolve Sudan"s government grew into the thousands on Monday as the country grappled with what its civilian leadership has called the biggest crisis of a two-year-old transition from autocracy. Protesters, including many who arrived by bus from outside Khartoum, were assembled by a coalition of rebel groups and political parties that have aligned themselves with Sudan"s military, which has accused the civilian political parties of mismanagement and monopolising power. The military has shared power with civilians in Sudan"s transitional authority since the removal of President Omar al-Bashir in 2019 after three decades in power. Civilian leaders have accused the military of seeking to execute a coup, in a war of words that began after a coup attempt in late September by Bashir loyalists. "We want the politicians to solve this problem and we want (Prime Minister Abdalla) Hamdok to dissolve the government," said Mohamed Abdallah, a 58-year-old man who said he had travelled from South Darfur. A "crisis unit" was being formed to bring together all sides to find a solution, the cabinet said in a statement following an emergency meeting. "History will judge us on our success to deliver our country and people to stability and democracy," Hamdok said in the statement. The sit-in, outside the usually off-limits gates of the Presidential Palace, began on Saturday following a demonstration against the civilian government. By Sunday, the crowd had thinned to hundreds, but by Monday afternoon the numbers had returned to around 2,000-3,000. They set up tents at the intersection of two of the capital"s main arteries, with a stage for speakers who called for the overthrow of the transitional government. Soldiers guarded the gates of the Presidential Palace. There was little police presence, except when protesters were blocked from marching on the nearby Cabinet Ministry. Pro-civilian political parties are planning their own demonstration on Thursday, the anniversary of a 1964 revolution. Meanwhile, a blockade of the country"s main port in the east of the country has entered its second month. Tribesmen blocking the port have similarly demanded the overhaul of the civilian government.