A parcel bomb exploded at the Jakarta office of a group promoting moderate Islam on Tuesday, seriously wounding three people including a policeman whose hands were blown off while examining the device.

The attack comes at a time of heightened tension between moderate Muslims and hardliners over religious minorities in Indonesia, the most populous Muslim nation.

A second bomb was sent to the former head of Indonesia’s Densus 88 anti-terror police, General Gories Mere, earlier in the day.

The explosion was the first bomb attack in the Indonesian capital since twin suicide bombings in July 2009 killed eight people and wounded 50 at the Ritz Carlton and JW Marriott hotels

Police, who confirmed the explosion had been caused by a bomb, were still struggling to identify the culprit and their motives, but a letter accompanying the bomb suggested the attack had been carried out by a radical Muslim group. If so, it signals a new more violent tactic by hardliners in the targeting of moderates opposed to shariah, or Islamic law.

The letter listed Indonesians “who have to be killed because they committed sins against Islam and Muslims”.

“I was standing behind the policeman and his hands blew off” said witness Ole Chavannes. “There was no bomb squad and the policeman was not wearing any protective equipment.”

Underlying resentment came to the boil last month when three members of a Muslim sect, Ahmadiyah, were killed by a mob of extremists claiming to defend Islam.

It was unclear who sent the explosive package addressed to Ulil Abshar Abdalla, a leading member of the ruling Democratic Party and the former co-ordinator of the Liberal Islamic Network.

“I never received any threats from anyone while I was still active at the Liberal Islamic Network,” Mr Abdalla told the local MetroTV broadcaster. “Why does this kind of thing happen after I joined a political party?”

The organisation Mr Abdalla used to head is disliked by conservative Muslims because it backs interfaith marriage.

The vast majority of Indonesian Muslims are moderate, but a radical fringe supporting Islamic law has become increasingly vocal in recent years in the emerging democracy of 240m people.

The government has in effect wiped out the Jemaah Islamiyah terrorist network behind a series of deadly bombings including the Bali bombings of 2002 and 2005 that killed more than 200 people.

Yet attacks against Christians and minorities sharply rose last year, signalling what experts say is a worrying trend for religious intolerance in a country with a constitution protecting freedoms of religion.

A widespread campaign against the Ahmadi has been openly backed in recent weeks by the religious affairs minister, the largest Muslim groups and the attorney-general.

Get alerts on Terrorism when a new story is published

Copyright The Financial Times Limited 2018. All rights reserved.

Comments have not been enabled for this article.

Follow the topics in this article