The temple has become a major battleground between right-wing Hindu groups and gender activists.
Tens of thousands of pilgrims have thronged the hilltop shrine since it reopened on Friday amid unprecedented security.
“We arrested 70 devotees after overnight protests around Sabarimala,” V N Saji, assistant commissioner of police, said.
The area has been increasingly tense with Hindu organisations and Prime Minister Narendra Modi’s Bharatiya Janata Party (BJP) opposing the Supreme Court order to let girls and women in the 10-50 age group in the temple.
There have been several protests and strikes.
Many pilgrims going to Sabarimala have also complained about restrictions on their movement during the new clampdown.
The Kerala government sent thousands of police to the region fearing a repeat of pitch battles around the temple in October, when the shrine first reopened after the Supreme Court ordered the lifting of a longstanding ban on women.
Police said many of those arrested late Sunday had been protesting against a ban on spending the night on the hilltop around the temple.
Devotees, many shirtless in line with the tradition followed by pilgrims, chanted mantras as they faced off with police.
“What the police has done is wrong. I am here with other locals to protest against the arrest of devotees,” Raghunathan Nair, one demonstrator said.
He was one of more than 100 people who protested outside a police camp, where all the arrested devotees were being held before their court hearing.
Dozens of women took part in protests, all chanting mantras and slogans.
Federal minister K J Alphons criticised the state government for the action.
As news spread about the arrests, protesters assembled near Chief Minister Pinarayi Vijayan’s residence in Thiruvanathapuram and shouted slogans.
“I fail to understand why the Kerala police has clamped prohibitory orders. This is not the way things should be handled. Sabarimala pilgrims are not extremists. You cannot use force in this place,” Alphons said in Nilackal, before heading to the shrine.
Minister for Devasoms (Temples) Kadakampally Surendran said it was not pilgrims but right-wing Rashtriya Swayamsevak Sangh (RSS) goons who had taken over the shrine, and defended the arrest of the protesters.
“Unlike Alphons who was a senior IAS officer, who later became a legislator with us and then moved on to greener pastures, I am only a simple political activist. But he should not have said things without knowing facts,” Surendran said.
Alphons said he would inspect how the state has utilised the Rs1bn relief fund from the central government. “I will go around the temple town to make sure how the funds have been used.”
Surendran said: “It’s true that the Centre has sanctioned Rs100 crore for various projects in Sabarimala and the deadline for implementing it ends in July 2019. Moreover the unprecedented floods saw close to Rs19 crore of work in progress in projects getting washed away in September. What happened in the temple premises last night was a takeover by the RSS goons. The police pleaded with them to return as it’s against the law to remain there. It was only after they refused to move that the police acted.”
Opposition Congress leader Ramesh Chennithala said it was most unfortunate that pilgrims are held in police custody and the state government should release them at the earliest.
“The prohibitory orders should be withdrawn immediately as there is no need for it. Vijayan has made a complete mess of the Sabarimala pilgrimage season as the police is creating havoc and has turned the temple town into a terror zone. Vijayan has lost control and he should demit the Home portfolio,” said Chennithala.