Authorities in Singapore say they have seized a "large number" of bank accounts that various media have linked to a Malaysian government-run fund that stirred controversy around Prime Minister Najib Razak. While Singaporean authorities didn't confirm the link, the move comes days after Switzerland said it would submit evidence of illegal transactions to Malaysian authorities, asking them to help pursue the investigation. The developments come just before Najib and other Southeast Asian leaders hold a special summit with U.S. President Barack Obama in California this month. Obama is strengthening ties with the region to help counter China's growing assertiveness in the South China Sea and to tap the region's large and fast-growing economies.