The People's Democratic Force to Overthrow Thaksinism (Pefot) yesterday ended its rally in front of Government House following negotiations with police.
A number of protesters agreed to return to Lumpini Park.
But about 300 refused to follow their leaders' orders to move the rally back to Lumpini Park and regrouped at the Uruphong intersection, forcing its partial closure to traffic.
Earlier yesterday, Pefot leaders held talks with police before deciding to end their rally to make way for Chinese Premier Li Keqiang's three-day visit, which begins today.
They have vowed to resume their protest at Government House after Mr Li's departure.
They agreed to shift venues on the condition that they be spared any legal action over the protest.
Deputy national police chief Vorapong Chiewpreecha and Metropolitan Police Bureau chief Kamronwit Thoopkrachang, representing national police chief Adul Saengsingkaew, held talks with Pefot leaders.
Pefot is led by retired top brass Adm Chai Suwannaphap and Gen Preecha Iamsuphan, as well as Thaikorn Polsuwan.
After a 30-minute discussion, Gen Preecha went on stage to address the protesters. He said Pefot core members had decided to move the protest back to Lumpini Park.
Pefot secretary-general Sub Lt Samdin Lertbut said the group would leave Government House temporarily.
He said the government has promised to allow them to resume their protests outside Government House after the Chinese premier's official visit ends. However, some of the protesters were angered by the decision and gathered in small groups to discuss their next move.
A large group of Pefot protesters decided to remain at Nang Loeng intersection. They later moved to Uruphong intersection, which lies outside the area in which the government imposed the Internal Security Act (ISA) to contain the protest.
The protesters are unhappy with the government, especially its attempts to push through amendments to the constitution.
A cabinet meeting on Wednesday imposed the ISA in Dusit, Pomprap Sattruphai and Phra Nakhon districts of Bangkok.
The ISA will remain in force until Oct 18 to deal with the anti-government protesters.
A total of 12,000 riot police were initially deployed to handle around 250 protesters, who gathered in front of Government House on Monday after moving from Lumpini Park.