BANGKOK, Jan. 16 -- Thai police are set to arrest Suthep Thaugsuban, leader of anti-government protesters as " Bangkok shutdown" entered into a fourth day on Thursday.

Deputy premier Surapong Tovichakchaikul announced that the police will take a scrupulous, well-guarded approach to arresting the protest leader, for whom a rebellion charge and arrest warrant have already been issued.

Suthep was said to have stayed at a hotel near Rajprasong intersection, which is among several others where the protesters have been occupying and blocking road traffic since Monday.

According to the police, about 40 guards believed to be armed with handguns were known to protect Suthep around the clock.

Surapong said the police will take the protest leader into custody without use of weapons but declined to comment whether gunfight might possibly occur between the police and his guards.

Suthep has also threatened to capture premier Yingluck Shinawatra and other members of the caretaker cabinet to force them to step down.

Meanwhile, three navy servicemen were arrested by police at a checkpoint near Government House Wednesday night. The sailors, including one lieutenant and two non-commissioned officers attached to the Navy Fleet, were found to have acted as guards for the Students and People Network for Reform of Thailand, another anti-government group which has joined hands with Suthep's People' s Democratic Reform Committee in the prolonged bid to depose Yingluck from power.

Three 9 mm. handguns were found inside their pickup truck with a false license plate, police said.

"It remains to be seen how many soldiers might probably be hired as guards for the protesters. The police are gathering information and will report to the Center for Administration of Peace and Order. The commanding units of those soldiers will also report to the CAPO about that," said Surapong, who currently heads the government's ad hoc body.

He also called on the protesters to stop laying siege to the Foreign Ministry's Consular Office where an estimated 4,000 people may obtain passports for overseas travels daily.

As part of the "Bangkok shutdown" the protesters have surrounded a dozen of government premises in the heart of the capital and its northern suburbs, forcing government staff to quit and denying people's access to them.

They have also paralyzed road traffic in Bangkok's business districts such as Sukhumvit, Patumwan and Silom since Monday.