Hiding under tables, slipping into storerooms and even clambering onto rooftops, hundreds of undocumented migrants, mostly from South and Southeast Asian countries, tried every trick to escape.

But in just two hours, immigration officers swept through Bukit Bintang and arrested 770 people.

Codenamed Ops Belanja, the raid transformed the capital's nightlife hub into a lockdown zone.

Streets usually buzzing with neon lights and tourists were sealed off as officers fanned out across three blocks, checking documents and flushing out those in hiding.

The immigration blitz began late Tuesday and continued into the early hours of Wednesday

Immigration officers sealed all entry and exit points along Jalan Nagasari and Jalan Ceylon, leaving those who tried to flee with nowhere to run.

The operation, which began at 7.30pm, involved 106 Immigration Department personnel from Putrajaya.

Immigration enforcement director Basri Othman, who led the raid, said 2,445 people were screened in total — 1,600 foreigners and 845 locals.

"Among those detained were 394 men and two women from Bangladesh, 235 men from Myanmar, 72 men from Nepal, 58 men from India, 17 men and two women from Indonesia, and nine others of various nationalities," he said at the scene.

He said the arrests were mostly for overstaying, not carrying valid identification papers and working without permits.

Many of these migrants come to Malaysia to escape poverty and unemployment in their home countries.

They are drawn by the promise of menial work in a more prosperous economy, taking up jobs in construction, plantations and other tough or hazardous sectors often shunned by locals.

Basri said the raid followed numerous public complaints about undocumented migrants in the area.

"Bukit Bintang has long been a hotspot. Its nightlife and location in the city centre make it a magnet for undocumented workers. We carried out a three-week surveillance before moving in last night," he said.

During the raid, officers also discovered a hidden gambling den fitted with closed-circuit television (CCTV) cameras. About seven to eight foreigners were caught playing online gambling and were detained.

Some shops in the area are operated by foreigners, creating a pull factor for others to gather.

Basri said the detainees will be taken to the Immigration Department headquarters in Putrajaya for initial screening before being sent to detention depots.

He said that enforcement efforts would continue.

"We will step up inspections on business premises to ensure employers hire foreign workers only within their approved quotas," he said.

No fake travel documents were found during the operation, but investigations into the detainees' background and employment status are ongoing.

The case is being investigated under the Immigration Act 1959/63, including Section 6(3), Section 15(4) and Regulation 39(b).