Bo Kyi, the joint secretary of the Assistance Association for Political Prisoners, a rights group at the Thai-Myanmar border, said the military government was merely exploiting the absence of the rule of law in the country.
"International pressure is working but the government is trying to find other ways around it, and releasing prisoners is one way.
"I think they are just trying to get more political support from the international community, especially Russia and China," he told Al Jazeera.
"On one hand, they are releasing prisoners but on the other they are arresting many more"
Assistance Association for Political Prisoners
"On one hand, they are releasing prisoners but on the other they are arresting many more. We need more domestic pressure in addition to international pressure."
Nearly 70 activists were arrested last year, he said.
Min Ko Naing, Ko Gyi, Pyone Cho, Htay Kywe and Min Zeya, released on Thursday, were key figures in the 1988 student demonstrations.
Since 1988, each has spent between nine and 15 years behind bars.
Myanmar has for years rejected and disregarded criticisms of its human rights policies by the international community.
Asean voices concern
On Wednesday, Asean foreign ministers voiced concern at the slow pace of democratic reform in Myanmar.
"We expressed concern on the pace of the national reconciliation process, and hope to see tangible progress that would lead to a peaceful transition to democracy in the near future,'' Alberto Romulo, the Philippine foreign secretary, said on the sidelines of the summit.
Hassan Wirajuda, the Indonesian foreign minister, said Myanmar should take the US draft resolution seriously and urged Asean to discuss the latest development.
But Nyan Win, Myanmar's foreign minister, asked Asean members to help block the US resolution at the UN, which would put global pressure on its military government.
China and Russia opposed the US resolution introduced on Tuesday, saying the UN Security Council had no grounds to get involved because Myanmar was not an international threat to peace and security.
"It bears to be repeated that Myanmar is a peace-loving nation and poses no threat to its neighbours or the region"
Thaung Tun, Myanmar's ambassador to Manila
Thaung Tun, Myanmar's ambassador to Manila, said his country has maintained friendly relations with neighbours and has been struggling to strengthen the economy and foster national unity.
"It bears to be repeated that Myanmar is a peace-loving nation and poses no threat to its neighbours or the region."
The US, in the draft resolution, also wants the unconditional release of Aung San Suu Kyi, Myanmar's opposition leader who has been under house arrest since May 30, 2003 and has spent about 11 out of the last 16 years in custody.
On Monday, Ban Ki-moon, the new UN secretary-general, issued a statement urging Myanmar to release all political prisoners.
The military government released nearly 3,000 prisoners last week, about 30 of them political detainees, in conjunction with Myanmar's 59th independence day celebrations.
Human rights groups say more than 100,000 convicts, including 1,100 political detainees, continue to be held in 42 prisons and 91 concentration camps in Myanmar.