LANGKAWI, Malaysia - The number of people confirmed dead after a boat carrying migrants from Myanmar sank near the Thailand-Malaysia border rose to 11 on Monday, authorities said, with about 70 people believed to have been on board the capsized vessel.

The status of another boat carrying 230 passengers remained unclear, Malaysian authorities said, adding that 13 survivors had been found so far. Thai authorities said they had recovered four bodies, including two children, adding to the seven found by Malaysia's maritime agency.

At a press conference on the island of Langkawi, close to the search area, Malaysia's maritime agency said air assets were being deployed by both Thailand and Malaysia to search for survivors.

ALSO READ: 1 dead, 10 rescued after migrant boat capsizes off Malaysia-Thailand waters

"We have got very good ... relations with the Thai agency so we have got good communication and exchanges of information," said Romli Mustafa, director of the maritime agency in Malaysia's Kedah and Perlis.

"It will be easier for us and our sea assets," he said of the use of air assets to support the search by boats, adding that the search operation could last seven days.

Romli said information received by the agency indicated a boat had departed Myanmar, near the border with Bangladesh, about two weeks ago, but some passengers had moved onto another vessel on Thursday.