Jakarta. Indonesia's Foreign Affairs Ministry has summoned Vietnam's ambassador to Indonesia Pham Vinh Quang to explain an incident involving an Indonesian Navy war ship and two Vietnamese coastguard boats in the Natuna Sea last weekend, the ministry said on Monday.

On Saturday, Indonesian Navy war ship KRI Tjiptadi-381 was involved in a tense skirmish with two Vietnamese coastguard vessels in North Natuna Sea.

According to a statement by the Indonesian Navy, the war ship had captured a Vietnamese fishing boat operating illegally on Indonesian waters.

The two Vietnamese coastguard boats, identified as KN 264 and KN 213, belonged to Vietnam's Fisheries Department.

When KRI Tjiptadi-381 started towing the fishing boat, the Vietnamese coastguard vessel KN 264 hit the war ship, while KN 213 bumped the fishing boat to sink it into the water.

Indonesian Navy officers rescued 12 crew from the fishing boat, but another two escaped by jumping into the sea. They were picked up by the Vietnamese coastguards.

Rear Admiral Yudo Margono, the commander of the Indonesian Navy’s 1st Fleet, said the incident happened within Indonesia's Exclusive Economic Zone (EEZ). 

Vietnam claimed the skirmish happened on its territorial waters.

The Indonesian Navy did not retaliate to the Vietnamese coastguards' provocations.

"The Vietnamese boat crew were taken to the Ranai Naval Base. They will face a legal process," Admiral Yudo said in a statement.

The Foreign Affairs Ministry revealed in a statement on its Twitter account on Monday that it has summoned Vietnam Ambassador Pham Vinh Quang to deliver an official protest over the incident. 

"The Foreign Affairs Ministry has delivered an official protest to the government of Vietnam through its embassy in Jakarta regarding the Vietnamese fisheries department boats' provocations against [Indonesian Navy war ship] KRI Tjiptadi-381," ministry spokesman Arrmanatha Nasir said.

The ministry is waiting to receive a complete rundown of the incident from the chief of the Indonesian Mlitary.

"Indonesia deeply regrets the incident involving Vietnamese Fisheries Department boats KN 213 and KN264 and the Indonesian Navy war ship Tjiptadi-381,” Arrmanatha said.

According to Arrmanatha, the Vietnamese boats' provocations had endangered the safety of the Indonesian ship crew and were in contravention of International Law.