A Chinese Foreign Ministry spokesman said relations between the 2,500 monks and police were "harmonious" after reports from Tibetan exile groups said police clashed with local residents and monks earlier this month.
The area around the monastery Kirti Gompa, founded in 1472 on the edge of Ngaba or Aba City, has been tense since Rigzin Phuntsog, a monk, set himself on fire and died in March.
Tibetan exile groups report that security forces surrounded the monastery last week, although there hasn't been independent verification of clashes with police.
Chinese Foreign Ministry spokesman Hong Lei denied reports of tensions in the vicinity of the monastery.
"According to our knowledge, the monks in the Kirti monastery enjoy a normal life and normal Buddhist activities and the local social order is also normal," he said.
They aren't short of food and supplies, as has been reported, he said. But security forces were checking the local population to "prevent unidentified people from entering" the monastery, Hong said.
Chinese media reported the death by self-immolation of Phuntsog but said he died of his injuries because local monks wouldn't allow him to remain in hospital.
"Shortly after he set himself on fire, a policeman on patrol found him, put out the flames and rushed him to a nearby hospital," a local government official said at the time. "But a group of monks from the Kirti Monastery forcibly took him out of the hospital later in the afternoon and hid him inside the monastery, regardless of his injuries."
After long hours of negotiation, the monks allowed Phuntsog's mother to take him back to hospital where he died the following morning, the official said.
The Tibet Post International, based in Dharamsala, India, said more than 33 people, at least eight of them monks, were arrested last week and police officers were walking around the monastery grounds and in buildings.
The monastery and surrounding towns in the mainly Tibetan area have been flash points in the past several years for anti-China protests, including demonstrations against the occupation of Tibet, an autonomous Chinese province adjoining Sichuan province directly to the west.
Many Tibetans in Sichuan are angry about what they see as a move by Beijing to move ethnic Han Chinese into the majority Tibetan areas of Sichuan province, in an effort to make Tibetans a minority.
In March 2008 four protesters in Aba were shot by security forces acting to contain anti-China demonstrations in the Tibetan regions, including in Lhasa in Tibet.
The latest alleged clashes shouldn't lead to more disturbances, Tibetans' main religious leader, the Dalai Lama, said.
The Dalai Lama, living in exile in Dharamsala, called for restraint on all sides of the latest confrontation around the monastery.
"I am very concerned that this situation if allowed to go on may become explosive with catastrophic consequences for the Tibetans in Ngaba," he said in a written statement.
"In view of this I urge both the monks and the lay Tibetans of the area not to do anything that might be used as a pretext by the local authorities to massively crackdown on them. I also strongly urge the international community, the governments around the world, and the international non-governmental organizations, to persuade the Chinese leadership to exercise restraint in handling this situation. "
He said the Chinese have used force to control the area since taking over what was an independent Tibet in 1950. This has "only deepened the grievances and resentment" of Tibetans, he said.
"I, therefore, appeal to the Chinese leadership to adopt a realistic approach and to address the genuine grievances of the Tibetans with courage and wisdom and to restrain from using force in handling this situation."