Olivia Rondonuwu – Indonesian militants are using parcel bombs and targeting minorities to try to push an Islamist agenda on the government and they could launch further small attacks, the country's anti-terror agency chief says.

Militant attacks and incidents of religious intolerance have risen in recent weeks, with mobs lynching three followers of a minority Islamic sect and torching two churches on Java island.

Parcel bombs have been sent to people involved in promoting pluralism and counter-terrorism in Jakarta. The head of the National Counter-Terrorism Agency, Ansyaad Mbai, said.

Islamic organizations that had not previously been involved in acts of terror were joining a militant network in Indonesia because of a convergence on certain issues.

"Terrorism is politics. The motive is politics, and clearly the militant network's aim is to affect political policy," Mbai said in an interview at his barricaded office in a former colonial building in central Jakarta.

Mbai said radical groups were putting pressure on the government to grant demands to dissolve the Ahmadiyah, a minority Islamic sect branded deviant by religious leaders.

Members of the Islamic Defenders Front (FPI), known for smashing up bars but not considered a terrorist group, have threatened to launch a revolution if the Ahmadi are not banned.

Mbai said the Islamist movement in the officially secular country would gain more ground if the government of President Susilo Bambang Yudhoyono, who has no clear stance on the matter, bowed to this demand.

"The president said that we can't be defeated by terrorism, but I say, if Ahmadiyah is dissolved, this country has been defeated," said Mbai, a former two-star police general.

Five parcel bombs were sent to the office and homes of pluralist and counter-terrorism figures this month, with one exploding and injuring three people. While there were no deaths, others in those fields are now fearful they could be next.

Indonesia has been successful in recent years in weakening Islamic militants and reducing the risk of bomb attacks such as those that killed over 200 people in Bali in 2002, but security in the capital has been stepped up after the parcel bombs.

"The bombs were the work of terrorist groups that have been doing terror in the past. The circuit, the type of explosives, the message and the targets carry the same signature," Mbai said.

Mbai said such groups could launch more attacks because they still had weapons, could recruit new members and had a stronghold in northern Sumatra island. However, security forces have killed or captured key figures of Indonesia's most infamous group, Jemaah Islamiah, in recent years.

JI, blamed for the Bali bombings, wanted to establish an Islamic state across Southeast Asia. Firebrand militant cleric Abu Bakar Bashir, accused of being the former head of JI, is being tried in court for allegedly funding a group in northern Sumatra that wanted to overthrow the government.

"There is a possibility of more terror attacks but the attacks would be weak because the militant groups are in a crisis of leadership," Mbai said.