The death toll in the sinking of a boat carrying asylum seekers off Indonesia last week has reached 20, even as police arrested four persons on the charge of smuggling people, police said on Monday.

A tugboat carrying more than 200 people sank on July 23 off the coast of West Java’s Cianjur district. Rescuers have so far found 189 survivors.

The four Indonesians arrested were taken into custody last Wednesday and Thursday in Cianjur and Soreang, another West Java district, said National Police spokesman Col. Agus Rianto.

West Java police spokesman Col. Martinus Sitompul said the four would be charged with people smuggling, which carries a maximum penalty of 15 years in jail and a fine of at least 500 million rupiah ($50,000).

The owner and skipper of the tugboat are being questioned.

The exact number of people missing is unclear because there was no manifest, but the overcrowded boat was carrying Iranians and Sri Lankans.

The Iranian group flew to Jakarta through Malaysia, and spent a day in the Indonesian capital, while the Sri Lankans came on a boat from Malaysia and spent one month in the West Java district of Bogor, before being transported to Cianjur, Mr. Sitompul said.

The vast islands that make up Indonesia and its proximity to Australia’s Christmas Island make it a popular exit point for the perilous journey. Hundreds of asylum seekers from war-torn countries have died in recent years trying to make the trip on rickety fishing boats.

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