CAIRO - Egypt's military rulers sternly warned protesters on Tuesday against "harming public interests" as demonstrators continued to lay laid siege to Cairo's largest government building and threatened to expand their sit-in to other sites in the capital.

The military also rejected criticism of its handling of Egypt's transition to democratic rule, vowing not to give up its interim role in managing the country's affairs until an elected government takes over.

It also pledged to produce binding regulations for the selection of a constituent assembly that will draft a new constitution, allaying fears by many Egyptians that Islamists -- likely to dominate parliamentary elections due in September -- would elect an assembly that would give the document an Islamic slant.

In a separate development, an Egyptian court on Tuesday convicted a Mubarak-era prime minister and two Cabinet ministers of corruption. Former Prime Minister Ahmed Nazif was sentenced to a one-year suspended sentence. Mubarak's long-serving interior minister, Habib el-Adly, was given a five-year jail term. El-Adly already is serving a 12-year term after being convicted of corruption charges in a separate case. He will serve the longer of the two sentences.

Former Finance Minister Youssef Boutros-Ghali was tried in absentia and given 10 years.

The military's warning to protesters Tuesday came ahead of a planned rally demanding a wider purge of members of Hosni Mubarak's regime and bringing to justice police officers accused of killing protesters during Egypt's uprising.

Several hundred protesters have been camping out since Friday at Cairo's Tahrir Square, epicenter of the Jan. 25-Feb. 11 uprising. They vowed not to leave until their demands are met. On Tuesday morning, 30 men armed with knives and sticks stormed the protesters' tent camp, wounding six, before they were forced out of the square by the protesters.

By early Tuesday evening, thousands more demonstrators made their way to the square as the day's stifling heat eased.

The military statement, read on state television by Maj. Gen. Mohsen el-Fangari, was the strongest public warning to protesters by the ruling generals since they took over from Mubarak when he stepped down on Feb. 11.

It was delivered in a threatening tone that suggested the generals may be close to running out of patience with the flurry of protests, sit-ins and strikes engulfing the nation since the uprising.

A growing number of protesters, meanwhile, see the ruling generals as an extension of the Mubarak regime and accuse them of showing too much respect for the ousted leader, who is formally under arrest but remains in a hospital at a Red Sea resort.

Ominously, the military statement called on Egyptians to "confront" any actions that prevent the return to normalcy. That was a thinly veiled warning to the protesters whose sit-in at Tahrir Square blocked traffic from the key plaza at the heart of Cairo. The protesters have laid siege to a major government building on the square and have threatened to expand their sit-in to the nearby Interior Ministry and the state TV building.

The military's statement warned against any "deviation" from peaceful protests and demonstrations in a way that could "harm public interests" and against spreading rumours leading to discord.

However, it said the military's response to offenders would be within the boundaries of "legitimacy." The statement did not elaborate, but rights activists at home and abroad say at least 10,000 people have been tried by military tribunals for alleged security offences since the army took over the streets from the police on Jan. 28.

The military also expressed its support for embattled Prime Minister Essam Sharaf.

The prime minister has recently come under growing pressure from protesters to do more to purge the police, civil service and the judiciary of remnants of Mubarak's regime and to speed up trials of those accused of corruption or the use of deadly force against protesters. Nearly 900 people were killed in the 18-day uprising.

Meeting one of the protesters' demands, Sharaf said on his Facebook page that he had accepted the resignation of Deputy Prime Minister Yahya el-Gamal, who has been widely criticized for his erratic behaviour, seeking publicity and reconciliatory approach toward businessmen backed by Mubarak's regime.

In a nod to the demands of some of the protesters, the military said it would draft a set of regulations for selecting the 100-member assembly that will write a constitution. Up to now, the military's roadmap to democracy only entailed a September parliament vote, the selection of the constituent assembly by the new legislature and presidential elections to be held late this year or early in 2012.

The Muslim Brotherhood, the country's largest and best organized political group, immediately voiced its opposition to the military's new proposal. Brotherhood spokesman Mahmoud Ghozlan said it contradicts previous declarations by the military and that it deprives parliament of its legitimate right to select the assembly.

"The only party responsible for deciding who are the members of the assembly that will write the constitution is the parliament," he said.

Egypt's state news agency, meanwhile, said the Supreme Judicial Council, Egypt's highest legal body, has decided to allow live transmission of the trials of Mubarak-era officials accused of corruption as well as police officers charged with killing protesters.

The footage will be relayed to screens installed outside courthouses for the public to watch, it said. Protesters have been complaining of the lack of transparency in these trials.