Indonesia has arrested 29 foreign-flagged boats for allegedly fishing illegally in domestic waters in July, a minister has said.

Maritime Affairs and Fisheries Minister Susi Pudjiastuti said on Monday that the vessels were mostly apprehended when they were sailing in Natuna waters in Riau Islands and hailed from neighboring countries, including Malaysia, the Philippines and Vietnam. Apart from fishing without legal documents, the vessels were found to have used prohibited fishing equipment, she went on.

"Customs and excise officers seized several pieces of evidence, such as 57 tons of fertilizer for fish bombing. The National Police also seized 2 tons [of fertilizer] in the Pangkajene Islands [Pangkep] and 1 ton on an uninhabited island around the islands," Susi said.

The confiscated fertilizer was allegedly brought into the country by Malaysian fishermen, the minister said.

Susi said at least four to five boats weighing about 50 gross tons (GT) were carrying fish bombs into the country's territorial waters every month, in which they sailed to Selayar Islands in South Sulawesi, East Nusa Tenggara, Bawean Island in East Java, until Raja Ampat in West Papua.

Susi said the National Police and the National Counterterrorism Agency (BNPT) were investigating further to determine whether the fishermen had intended to use the bombs for fishing activities or use them for terrorism-related purposes.

Despite the government's efforts to ban fish bombs, the use of them has continued in domestic waters. Susi said officials would continue to spread awareness, especially among fishermen in fishing zones, on the need to stop destructive fishing activities. (ebf)