Indonesian authorities ruled out that an attack injured two soldiers on Tuesday morning after a smoke grenade detonated near Jakarta’s national monument.

The blast occurred at around 7:00am local time (1200 GMT) as military and police personnel were taking a morning jog around the leafy grounds in the centre of the capital.

“We’re now investigating why the smoke grenade was there,” Jakarta police chief Eddy Gatot told reporters, adding that the two injured had been rushed to the hospital.

“One of them was wounded on the hand and the other was injured on the leg,” he said.

There are military barracks on the grounds of the national monument.

The Indonesia Automatic Fingerprint Identification System unit and the elite Gegana bomb squad were deployed to investigate the site of the explosion but by 10am the area had reopened to the public.

Gatot said there was no indication of an attack. He told the Jakarta Post that the smoke grenade “could belong” to security personnel who happened to have “left it there” by accident.

Jakarta military chief Eko Margiyono also stressed that there was no indication that the explosion was anything but an accident.

“This wasn’t something extraordinary,” he added.

Indonesia, the world’s biggest Muslim majority nation, has long struggled with Islamist militancy and has suffered regular attacks.

The Jakarta Post reported that a day prior to the incident at the National Monument, Muslim activists had gathered at the site to commemorate the third anniversary of a 2016 rally held to demand the prosecution of then-Jakarta governor Basuki “Ahok” Tjahaja Purnama for blasphemy.

The grounds surrounding the monument referred to locals as Monas, house a number of ministerial buildings and the office of Indonesian President Joko “Jokowi” Widodo.

Presidential spokesperson Fadjroel Rachman said Jokowi continued with his schedule as normal at the State Palace, holding meetings with ministers and preparing for a presidential lecture slated for 2pm on Tuesday.

Jokowi himself heard about the explosion from the media and called for law enforcers to “take stern measures” if someone was found guilty of perpetrating the incident, he said.

In October, the Indonesian president ordered that security be beefed-up after two militants linked to the Islamic State terror group stabbed his chief security minister ahead of Jokowi’s second inauguration.

The security minister survived the attack, which led to the arrests of dozens of suspects.

Six people were injured last month after a 24-year-old university student blew himself up outside police headquarters in the Indonesian city of Medan.

THE JAKARTA POST/ANN/AFP