Nani Farida and Apriadi Gunawan, Banda Aceh/Medan – A series of bomb explosions punctuated the celebration of Independence Day in conflict-torn Aceh, as another bomb explosion rocked a hotel in Medan, capital of North Sumatra. It was believed to be connected with the shooting dead of two members of the Free Aceh Movement (GAM) in the city on Friday.

Celebrations in other conflict-torn provinces went ahead peacefully.

A homemade bomb exploded in a field in Blang Padang, where hundreds of local officials were attending an Independence Day celebration early on Saturday, leaving 13 people injured.

The victims, several in a critical condition, were rushed to the Zainoel Arifin general hospital in the city. Fikri and Husain, also in critical condition, were taken to Medan for intensive care.

The explosion, which shocked ceremony participants, occurred after two children with a bicycle accidentally disturbed a plastic bag that contained the bomb, detonating it.

The night before the celebration, several bombs also exploded and gunfights took place between security personnel and rebels at separate locations in the city and in Lhokseumawe, but no casualties were reported.

Two security personnel were injured in another bomb explosion while both were on patrol in the city on Friday night.

At the same time, another bomb rocked the office of the Syah Kuala subdistrict chief, while two gunfights broke out between security personnel and rebels in separate locations in Blang Bintang.

The situation in major cities in the province has been tense since GAM called for a mass rally while local authorities called on the public to celebrate Independence Day in the customary fashion.

Public transportation stopped running after a passenger bus was burned by unidentified gunmen near Bireuen on Thursday, and almost all shops remained closed.

On Friday, more than 700 people, including students, held a mass rally, demanding independence for the province.

Local officials blamed GAM for the bombings, with a strong warning that they would take tough measures against it unless it stopped resorting to violence.

Aceh Besar Police chief Adj. Sr. Comr. Alfons said the police had discovered that rebels had infiltrated the celebration site by wearing civil servant uniforms.

He said the local police and military would continue to carry out searches around the city in anticipation of possible future action by GAM.

Chief of the Iskandar Muda Military Command (overseeing security in Aceh) Maj. Gen. Djali Jusuf said he had ordered all personnel deployed in the province to improve security in areas likely to be the target of bombings, in Aceh Besar, Pidie and North and East Aceh.

"All personnel have been ordered to take tough action against anyone who tries to disturb security and order," he said.

In Medan, North Sumatra Police chief. Insp. Gen. Ansyaad Mbaai said the bombing at Best Western Hotel Asean International had a close link with the killing of two GAM rebels in the Sunggal area of the city. "The two people who threw the grenade escaped a gunfight with the local police in Sunggal. We are looking for them," he said.

Lukman and Abdullah, who had cellular phones containing secret GAM call signs were killed in the gunfight, while two others escaped.

Mbaai said the police were cracking down on certain locations in the city used by GAM as new supply points.

Eighty rebels had been killed in the city over the last two years, he added.

GAM spokesman in Banda Aceh Tengku Radak claimed responsibility on behalf of GAM for the bombings, which, he said, were aimed at expressing GAM's hatred of the military.

"The military has insulted the Acehnese people, who were forced to raise the national flag despite their unwillingness. Many villagers were beaten because they wouldn't raise the Indonesian flag," he said.

He cited as an example Suwarni Abdullah, a 17-year-old high school student from Cot Teube, Bireuen, who was shot at by security personnel for refusing to raise the national flag in front of her house.

Indonesian Military (TNI) Commander Gen. Endriartono Sutarto, still fresh from his two-day visit to the province, condemned GAM for the series of bombings, saying security authorities would take tougher action against them.

"The security authorities cannot properly cover such a large province. Despite the bombings and clashes, the situation in the province remains under control," he said after participating in the Independence Day celebration at Merdeka Palace on Saturday.

The government is scheduled on Monday to determine the action necessary to end the prolonged conflict in Aceh.

Celebrations of Independence Day went off peacefully in Papua, Maluku and Poso.

Papua Governor Jaap Salossa, who led the official ceremony to mark Indonesia's 57th anniversary of independence, voiced his appreciation of the Papuan people's nationalism. He said many people had talked about independence only, whereas they really supported the Indonesian unitary state.

On Thursday, hundreds of former political inmates staged a peaceful demonstration in Jayapura, capital of Papua, demanding the territory's separation from Indonesia. They said that Papua was not one of the territories that declared their independence as the Indonesian unitary state on August 17, 1945.

Chief of the Wirabuana Military Command (overseeing security in Sulawesi) Maj. Gen. Amirul Isnaeni said more than 100 combat soldiers had been deployed to Poso.

"The reinforcements are needed to deal with the reemergence of violence in the formerly restive regency over the last several weeks," he said in Makassar, South Sulawesi.