Philippine National Police (PNP) chief Director General Ronald Dela Rosa points at a part of an Improvised Explosive Device (IED) found near the US Embassy during a press conference in Manila, Philippines November 28, 2016. Photo: Reuters/Romeo Ranoco

Philippine police conducted a controlled detonation of a homemade bomb found in a trash bin near the US embassy in Manila on Monday and said militants sympathetic to Islamic State could have been responsible.

National police chief Ronald dela Rosa said components of the improvised explosive device suggested it could have been planted by the Maute, a Muslim rebel group that has pledged allegiance to Islamic State.

Maute’s fighters were locked in a standoff with the military for a third day in the country’s south. More rebels were reported killed on Monday, taking the number of dead to 19.

“We could theorize that they could use this as a diversion,” dela Rosa told a news conference.

The embassy had no immediate comment on the discovery of the bomb, which was left about 200 meters from the compound. Business there continued as normal, with dozens of Filipinos queuing outside for visa applications.

An 81 mm mortar round was used as an explosive device and that was a signature of the group, dela Rosa said. Similar components were used in a September 2 bombing in Davao, which killed 15 people and wounded about 70.

Maute were blamed for that attack, and four of its members were arrested and found with video clips of them pledging allegiance.

Dela Rosa said intelligence operations would be stepped up and checkpoints would be set up around the capital.

Dangerous discovery in Indonesia. Photo: Antara Foto/Reno Esnir/via Reuters

Since the Davao bombing, the Philippines has been under what is termed“a state of lawlessness,” allowing the military to support the police, if required by the president.

That has led to frequent speculation that martial law could be declared to support President Rodrigo Duterte’s deadly drugs war, something his office has repeatedly dismissed.

“For God’s sake, the government will not use an incident that will cause panic, fear and undue harm to declare martial law,” he said.

In Lanao, a restive southern province, soldiers battled the Maute group to retake an old town hall building, sending hundreds of residents fleeing.

Army spokesman Major Filemon Tan said about a dozen soldiers had been wounded in an air-and-ground assault.

Two days ago, police in Indonesia arrested a suspected Islamist militant and seized a large quantity of bomb-making material that he planned to use in attacks on government buildings and the Myanmar embassy in Jakarta next month, a police spokesman said.

The suspect, arrested at his home in Majalengka regency in West Java earlier this week, was identified as Rio Priatna Wibawa, 23, who is believed to be a member of an Indonesian group that supports Islamic State.

Local media reported that the amount of explosives seized would have resulted in a blast twice as powerful as the bomb that killed 202 people in a Bali nightclub in 2002.

Police also confiscated some books, a black flag, rounds of bullets and several weapons, including an air rifle and a machete, police spokesman Boy Rafli Amar told a news conference on Saturday.

“We are now trying to prove how he had planned everything, whether he was working alone and how he managed to get the money to buy that much explosive material,” he said.

Wibawa, who studied agricultural science at university and was unemployed, was a self-taught bomb-maker who had planned to distribute explosives to several places across Indonesia, Amar said.

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