One day after a boat laden with more than 500 Muslim Rohingya beached off the coast of Indonesia, around 1000 more migrants have washed up on a Malaysian resort island.

Langkawi police said that three vessels arrived during the night to offload Bangladeshi and Myanmar migrants, but one remained stuck on a breakwater early Monday morning.

Chief Supt Harrith Kam Abdullah told Anadolu Agency that local authorities had now detained all who had come ashore.

"There was 1,018 people and we are expecting more. They were carried by three boats into Malaysia and this is the work of a [people smuggling] syndicate," said Abdullah. 

The number is believed to include around 100 women and 50 children. 

"We are investigating the detainees to find more information on the syndicate and agent details," he added. 

On Monday, a further 400 migrants were also picked up on Indonesia's north-western coast of Aceh, taking the number of Bangladeshi and Rohingya (which the United Nations considers the world's most persecuted ethnic minority) who have landed in the country by sea over the last two days to more than 900.

Indonesia's Deputy Minister of Foreign Affairs Abdurrahman Mohammad Fachir told liputan6 news outlet that the "government will now investigate the reason why they washed ashore."

The beachings follow the May 1 discovery of the bodies of 33 Rohingya and Bangladeshi migrants at an abandoned people smuggling camp in Southern Thailand -- over Malaysia’s northern border.

Thai authorities have since transferred 53 policemen based in the southern provinces of Songkhla, Ranong and Satun -- where smuggling of Rohingya is widespread -- to inactive posts.

According to Thailand's Nation newspaper, another 15 police officers have faced similar sanctions on suspicion of benefiting from trafficking or due to “incompetence.”

Langkawi Police Chief Abdullah promised Anadolu Agency similar action on Monday.

"Stern actions will be taken," he stated. 

In the wake of the crackdown, the boats containing the migrants appear to have been abandoned off the coast -- the smugglers fleeing rather than venturing ashore and facing the chance of capture. 

In the process, migrants have been left to stagger -- or often swim -- towards land.

Chris Lewa, the director of the Arakan Project, has told Anadolu Agency that increased pressure from Thai authorities had now forced smuggling camps offshore, with many Rohingya and Bangladeshi now held off the Thai coast.

The Head of North Aceh Police, Adj. Com. Achmadi, told tempo.com on Monday that many of the 400 who had come ashore in Indonesia had said that the smugglers had abandoned their boat after it ran out of fuel, and they had been bobbing about on the ocean for weeks.

He said that fisherman had found them in a weak condition, with very little supplies.

A migrant named Razu who had travelled on one of the boats told portalsatu.com that he had left Myanmar with hundreds of other Rohingya in two boats, but after so many had died they all clambered onto the one.

"The crew of the boat prohibited us from talking, eating food or drinking," he said. "Anyone who argued was struck or killed, and their body thrown into the sea."

Aceh Police head Achmadi -- many Indonesians use only one name -- said Monday that those discovered off Aceh had been transferred to mosques and another shelter in Seunundon Sub District, where they came ashore.

“They have been moved to a sports center and the hall of a police office in North Aceh to make data processing easier,"  he said, according to tempo.com.

He added that the total number of refugees in the two shelters was now more than 600 and would probably increase.

The head of Indonesia's Ministry of Manpower and Transmigration, Jailani, said Monday that food and health services would be supplied to the migrants in the shelter until immigration agencies take over.

Razu - a Rohingya migrant - said he had to leave Myanmar as he had been tortured by security officers and lost all of his family.

“My father, mother, and grandfather have been killed by the army," portalsatu.com reported him as saying.

"Burma [Myanmar] does not want us. If we go back there, our souls are threatened."

He said he was trying to get to Malaysia to find a job but had been cheated by the crew of the boat who left them on the ocean.

"I want to live in Malaysia or Indonesia, where I can find job and save," he stated.

The May 1 discovery of the corpses has shocked Thailand, which is under heavy pressure from the U.S. and European Union for its paltry record on human trafficking. 

Last year, it was given the lowest possible ranking in a U.S. State Department's human trafficking report, while earlier this month the E.U. gave Thailand six months to improve efforts in combating illegal fishing by trawlers on which migrants are used in “slave-like conditions.”

Most of the Rohingya who fall victim to the smugglers are from Rakhine state in Western Myanmar. 

After violent clashes in the summer of 2012 with Buddhist Rakhine, they began to flee en masse to find safety and work in Malaysia and beyond. 

At first, they boarded rickety boats controlled by human smugglers -- which sometimes sank during the trip across the Andaman Sea -- but since last year they have been travelling on larger vessels.

Bangladeshis are also increasingly using human smugglers to go to what they see as the economic promise of Malaysia. But some of them -- along with the Rohingya -- are kidnapped and forced to board the boats.

 The United Nations' refugee agency UNHCR has said that around 25,000 Rohingya and Bangladeshis have boarded people smuggling boats in the first three months of this year -- twice as many as during the same period in 2014.

Anadolu Agency