A tense situation has developed at the headquarters of Myanmar's ruling Union Solidarity and Development Party (USDP), where those attending a party meeting are not being allowed to leave by security forces.
Sources told VOA's Burmese service that a conflict had developed between President Thein Sein and party leader and parliament Speaker Shwe Mann.
The speaker's assistant told VOA that the situation was very complicated and would be settled Thursday morning. He confirmed that Shwe Mann's security guards had been interrogated by special branch police. But Shwe Mann's status and whereabouts weren't known.
His son, Toe Naing Man, confirmed to VOA that the USDP building in Naypyidaw had been shut down Wednesday night, allowing no one to enter or leave.
Another source inside the building, who did not want to be named, told VOA that security forces were inside the party headquarters and were preventing anyone from leaving.
VOA witnessed official cars used by ministers entering and leaving the compound, and some staffers were seen carrying in bedrolls.
There were unconfirmed reports that Thein Sein would hold an emergency meeting of his cabinet Thursday morning.
Earlier this week, 149 senior officers retired from their army posts to run as USDP candidates in the upcoming elections. But at the party convention Wednesday, only 59 of the former army officers were accepted as candidates.
The Election Commission's deadline for parties to submit candidate lists is Friday.
Tensions between USDP factions and the military surfaced in June, when the party backed a motion that would have ended the military's de facto ability to veto constitutional amendments.
The measure also was backed by the opposition National League for Democracy (NLD), which had collected 5 million signatures in support of the reform.
But Myanmar's military, which opposed the measure, has a constitutionally guaranteed 25 percent of seats in parliament, enough to block constitutional reforms it does not like.
General elections scheduled for November will be the first since the country ended decades of military rule in 2011. Thein Sein said he would not run for a seat in parliament, but that would not prevent him from being elected by legislators for a second term in office.
The NLD, led by Nobel Peace Prize laureate Aung San Suu Kyi, said it would contest almost all of the available seats in parliament and expected heavy gains in the legislature.