The office of the Swiss Attorney General announced the seizure on Wednesday, amid a probe into several people linked to the heavily indebted 1Malaysia Development Fund (1MDB), including Malaysian Prime Minister Najib Razak.

Swiss authorities said the accounts, which contained millions of dollars, were frozen amid suspicions of corruption and money laundering.

Malaysian leader Najib has been under growing pressure to resign since "The Wall Street Journal" revealed in early July that Malaysian investigators had found nearly $700 million (620 million euros) in mysterious deposits in his personal bank accounts.

The money had been withdrawn from 1MDB's bank accounts. The fund was set up by Najib in 2009 to boost Malaysia's economic prospects.

It was unclear whether the accounts frozen in Switzerland were directly linked to funds received by the Malaysian leader.

Najib denies any wrongdoing, describing criticism of his leadership as a "political conspiracy." Officials maintain the cash came from "political donations" from Middle Eastern countries.

Former Malaysian premier Mahathir Mohamed has joined the call for Najib to step down.

The 90-year-old, who himself ruled Malaysia for 22 years, spoke at huge rallies last weekend, accusing Najib of bribing politicians in the ruling United Malays National Organization (UMNO), to secure their support.

Tens of thousands of people joined an anti-government protest in Kuala Lumpur over the weekend

Huge protests over the weekend, led by Bersih, a coalition of Malaysian NGOs and activist groups, were declared illegal by police, and several organizers were brought in for questioning.

On Wednesday, German-based Transparency International said Malaysia's fight against corruption wouldn't be credible until the truth about Najib's sudden personal windfall was revealed.

mm/msh (AFP, AP)