No Malaysians involved in East Jakarta bombing: Ministry of Foreign Affairs

The suicide bombings at the busy bus station in East Jakarta-an attack that killed three policemen and injured 12 others on Wednesday night-has put authorities on alert to remain vigilant in anticipation of further attacks.

"There has been a bomb, for now we suspect it is a suicide bombing", deputy national police chief Syafruddin, who like many Indonesians goes by one name, told TV station TVOne.

Mr Wasisto said five civilians were also injured.

But authorities are increasingly anxious about a surge in radicalism, driven in part by a new generation of militants inspired by ISIS.

Earlier, a police spokesman told reporters that police were investigating whether the attackers had direct orders from Syria or elsewhere.

"I convey my deepest condolences to the victims and their families - especially the police officers who passed away while performing their duty", he said in a televised address.

The blasts are the latest in a string of attacks since 2010 that have targeted police, who are seen as the enemy due to Detachment 88, which has been the major agency arresting and in some cases killing people involved in pro-Islamic State cells.

Indonesia has always been in war against armed groups but in recent years hundreds of terrorists have gone to Islamic State of Iraq and the Levant (ISIL) in Syria and Iraq for fighting.

"This is Indonesia, home for all of us #FailedTerror #WeAreNotAfraid", the Indonesian Air Force tweeted.

"A bomb explosion has occurred and for now it is believed to have been a suicide bombing".

The terminal is a local hub served by minibuses and buses.

Police officers clear the area around the site of an explosion in Jakarta, Indonesia, Wednesday, May 24, 2017. He spoke from his hometown of Solo in Central Java province.

A gun and suicide attack in Jakarta killed four attackers and four civilians in January past year, and was the first assault claimed by the Islamic State group in Southeast Asia. He said the suspected attacker's head was found in a bus stop and his hand was on the road.

Muslim-majority Indonesia has carried out a sustained crackdown on militants since the 2002 Bali bombings by al-Qaida-affiliated radicals that killed 202 people.

JAD was designated a terrorist organisation by the United States in January, which said the network was an umbrella group for about two dozen extremist outfits.