▲ The aftermath of suicide bombings at the Kampung Melayu bus station, one of the busiest transit hubs in Jakarta, on Wednesday

JAKARTA, Indonesia — Two suicide bombers set off explosives at one of Jakarta’s busiest transit hubs on Wednesday night, killing three police officers and wounding at least 10 other people, the police said.

The blasts occurred about five minutes apart at the Kampung Melayu bus station, which links the sprawling eastern suburbs and the industrial areas to the north.

“So far, the death toll consists of three policemen, two suicide bombers,” Setyo Wasisto, a spokesman for Indonesia’s national police, told reporters. Five police officers and five other people were hurt, he said.

There had been a large police presence at the station for a parade, part of the city’s activities leading up to Ramadan, which begins Saturday.

The motive for the attack was not clear, and by early Thursday, no group was known to have taken responsibility.

Indonesia’s president, Joko Widodo, sharply condemned attacks while on a trip to his hometown in Surakarta, Central Java.

“These victims are known to us. They are police. They are bus drivers. They are motorcycle taxi drivers and grocers,” Mr Widodo said. “I have ordered the police to hunt the terrorists and get to the root of this attack.”

Since early last year, there have been several low-level attacks in Indonesia by Islamic State sympathizers. The authorities say hundreds of Indonesians may have received training from the extremist group in Iraq and Syria.

In January 2016, militants killed four people in a gun and bomb assault in the heart of Jakarta, Indonesia’s capital.

The attack on Wednesday occurred amid increasing political, religious and ethnic tensions in Jakarta and across the country.

Earlier in the day, Basuki Tjahaja Purnama, Jakarta’s governor, resigned. On Tuesday, he had dropped his appeal of a conviction for blasphemy, for which he was sentenced to two years in prison.

As his politically charged trial was taking place, Mr. Basuki, who is Christian and ethnically Chinese, lost his bid for re-election in a landslide last month.

He had been leading in polls when he was accused of violating blasphemy laws by citing a verse from the Quran in a speech last September to argue that it was acceptable for Muslims to vote for a non-Muslim candidate. Hard-line Islamic groups accused Mr. Basuki of blaspheming Islam and the Quran and held several large street protests, one of which turned violent, demanding that he be jailed or executed.

On Wednesday night, before the transit station bombing, thousands of white-clad Muslims filed down one of the busiest thoroughfares in central Jakarta to celebrate the resignation of Mr. Basuki, who is widely known as Ahok.