In a sign of growing unrest within Myanmar's ruling Union Solidarity and Development Party, Shwe Mann, the party's chairman and parliament speaker, was ousted Thursday, according to reports.

The move follows a day after Myanmar security forces entered USDP headquarters while a meeting was in progress about the upcoming elections and barred its leaders from leaving the building. President Thein Sein and Shwe Mann, who reportedly has presidential aspirations, have been at odds over the choice of candidates for the elections, Reuters reported, citing party sources.

"Shwe Mann isn't the chairman of the party anymore," a member of parliament for USDP said anonymously, according to Reuters, adding: "He's in good health and at home now." Shwe Mann, however, will retain his position as parliament speaker.

Party members also said Thursday, according to Reuters, that party vice president Htay Oo was appointed as the new chairman. Htay Oo, who is believed to be close to Thein Sein, will continue to hold the post of party vice chairman.

“Police entered the party compound last night. Since then no one was allowed in or out,” Toe Naing Mann, Shwe Mann's son, told Agence France-Presse Thursday, adding that there were also guards at his father’s house. "It is strange that armed forces have restricted a political party in this way," Toe said.

Myanmar, which will hold elections on Nov. 8, was ruled for 49 years by the military, which continues to retain an effective hold over the country's political system. Constitutional amendments have been proposed to loosen the grip of the military, but any change to the constitution needs 75 percent votes and the military, which has 25 percent of the seats in parliament, gets an effective veto over the proposed changes. In June, a vote to reduce the support votes to 70 percent from 75 percent, did not pass.

Nobel laureate Aung San Suu Kyi, who leads the opposition National League for Democracy Party (NLD), has called on the military to withdraw from politics. Shwe Mann, who had publicly warmed up to the idea of working closely with Suu Kyi, chose to oppose the military during constitutional reform debates discussing a reduction in the military’s power, the Guardian reported.

The NLD is expected to pose a challenge to the ruling USDP, which was created in 2010, during the elections that will be contested for a total of 498 seats for lower and upper houses, 644 region and state parliament seats, and 29 national races seats, according to the Associated Press. About 83 parties are currently registered, according to the election commission list.