KUALA LUMPUR (AFP) - Malaysian authorities have found the bodies of 11 more Indonesian migrants including a young girl, taking the toll from last week's boat tragedy to 61, a coast guard official said on Monday (Sept 7).

The 11 bodies were fished out from the sea late Sunday, Mohamad Aliyas Hamdan, a Malaysian Maritime Enforcement Agency official, told AFP.

Thirty-seven of the victims were men, plus 23 women and a three-year-old girl.

Twenty Indonesians who have been rescued are in good health and are being detained by the coastguard, he added.

Officials have said the overcrowded wooden boat capsized and sank in rough seas about 16km off central Malaysia's Selangor state before dawn on Thursday.

Aliyas said the group were leaving Malaysia to return to Sumatra in Indonesia, across the Malacca Strait.

Survivors have reportedly said there were up to 80 people on the small vessel but local fishermen who helped in rescue efforts said there could have been up to 100.

Malaysia is Southeast Asia's third-largest economy and a magnet for migrant workers from its poorer neighbours, with the vast majority coming from Indonesia.

About two million Indonesians, many of them working illegally, are now in Malaysia doing a range of generally low-paid jobs.

Deadly accidents in the strait are not uncommon, with travellers typically attempting the crossing in rickety vessels and often at night to avoid detection.

In June 2014 more than a dozen people drowned when a boat overloaded with around 100 Indonesians sank while taking passengers home for the Islamic fasting month of Ramadan.