The bodies of at least 13 people, identified as "illegal" Indonesian migrants, washed ashore on a beach in the southern Malayasian state of Johor on Tuesday, according to reports.

The boat is believed to have capsized after it was hit by strong waves near Bandar Penawar off the coast in Bandar Penawar near Kota Tinggi town, Channel News Asia quoted Kota Tinggi Police chief Supt Rahmat Othman as saying.

"ID cards from Indonesia were found" on the 13 deceased, The Sydney Morning Herald quoted Indonesian Foreign Ministry spokesman Armanatha Nasir as saying.

The bodies of all 13 victims — nine women and four men — were shifted to a local hospital. They were believed to be crossing the sea illegally.

"If they were on a legal boat, all safety conditions would be met. When you try to cross illegally, of course you compromise with these safety measures," CNA quoted Deputy Inspector General of Police Noor Rashid Ibrahim as saying.

A team of 16 marine police personnel and seven policemen have been deployed to search others as up to 35 people were believed to be on the boat when it capsized.