Indonesian Army Special Forces and police commandos have been deployed to secure King Salman Abdulaziz Al Saud's trip to Jakarta and Bali.
It was the same last weekend with security forces in Malaysia, the first stop of the King's month-long seven-nation tour.
In Indonesia, his motorcade includes several armoured vehicles, his personal bodyguards and Indonesian troops. He will continue to travel under heavy guard while he is on vacation in Nusa Dua.
Bali deputy police chief Syafruddin said 5,000 security personnel would be on hand to ensure his safety and privacy on the resort island.
Together with officers deployed across Jakarta and Bogor in West Java, Indonesia would have assigned some 10,000 men on the King's protective detail.
The enhanced security comes after Indonesia and Malaysia were hit by their first terror attacks claimed by the Islamic State in Iraq and Syria (ISIS) last year.
The two Muslim-majority countries in South-east Asia have also seen a surge in domestic terrorist activities in the past year.
Last Monday, a gunman from a terror cell in Indonesia with ties to ISIS was killed in a shoot-out with police in Bandung, West Java, after he and an accomplice set off a home-made bomb in a park.
A week earlier, Malaysian Special Branch police nabbed seven men,including four Yemenis - all with links to ISIS - over a plot to mount a vehicle-bomb attack.
Both incidents came just days before the King was due to arrive in the two countries for bilateral meetings.
King Salman has always taken a firm stance against Islamic extremism, giving the green light for Saudi Arabia to be part of the United States-led coalition behind air strikes against ISIS since 2014.
In December 2015, the kingdom formed a coalition of 34 countries, including Middle Eastern, African and Asian states - to fight terrorism in the Islamic world.
Last week, the King called on Indonesia to close ranks against terrorism during his address to lawmakers in Jakarta. The two countries have also signed an agreement to cooperate on counter-terrorism.
National police spokesman Martinus Sitompul said on Friday that Indonesia's Detachment 88 counter-terrorism unit will follow up with the Saudi police on the pact.