Dhaka: Bangladeshi police arrested three human traffickers on Monday after killing four in recent days and arresting more than 100 in recent months as the country cracks down on people smuggling amid an Asia-wide crisis, an officer said.

There has been a huge increase in refugees from Bangladesh and Myanmar drifting on boats to Malaysia and Indonesia in recent days after Thailand, usually the initial destination in the people smuggling network, announced its own crackdown on trafficking.

Three traffickers, accused of smuggling of thousands of people, were arrested in a raid in the southern Bangladeshi coastal town of Teknaf in the Cox's Bazar district, close to the border with Myanmar.

‘We have produced them before the court while another fled during the drive,’ Mohammad Ataur Rahman Khandaker, a senior police officer in Teknaf, told Reuters.

On Friday and Sunday, four ‘notorious’ traffickers were killed in gunfights with police, he said.

An estimated 25,000 Rohingya Muslims from Myanmar and Bangladeshis boarded people smugglers' boats in the first three months of this year, twice as many in the same period of 2014, the U.N. refugee agency UNHCR has said.

The migrants brave perilous journeys to escape religious and ethnic persecution and poverty. The UNHCR estimated that 300 people died at sea in the first quarter of 2015 due to starvation, dehydration and abuse by boat crews.

They were often trafficked through Thailand, a predominantly Buddhist country, and taken into the country's jungles, where traffickers demanded ransom to release them or smuggle them across the border to mainly Muslim Malaysia.