Indonesian police arrested seven suspected members of the southeast Asian terror group Jemaah Islamiyah (search) and seized a large cache of explosives and weapons from a bomb-making factory, officials and media reports said Friday.

One of the suspects committed suicide Friday while in police custody in Jakarta, police said. Two other suspects were arrested Tuesday in Jakarta (search), and four more were arrested Wednesday in the central Javanese town of Semarang, where the explosives were seized.

The arrests and seizures were the latest in a series targeting suspected Islamic militants (search) in the world's most populous Muslim nation after last year's bombings on the island of Bali killed 202 people, most of them foreign tourists.

All four men arrested in Semarang were suspected members of Jemaah Islamiyah, the group blamed for the Oct. 12 Bali bombings, Widayadi said, adding officers were investigating whether they were linked to the attack.

Brig. Gen. Edward Aritonang confirmed the arrests and explosives seizures, but referred further inquiries to the national police chief who was in Semarang to oversee the operation.

Earlier Friday, police said they had arrested three suspects in the capital, one of whom allegedly committed suicide at a police security post after he was detained Friday.

Jakarta police chief Gen. Makbul Padmanegara said 28-year-old Ihwanudin, who was handcuffed, grabbed a weapon from an officer during questioning, ran into a bathroom and shot himself in the chest.

When reporters questioned the likelihood of a handcuffed suspect being able to kill himself, Padmanegara said: "I swear to God this is how it happened."

The two other suspects, identified as Pranata Yuda and Sihyono, were arrested in Jakarta on Tuesday, Padmanegara said.

Offices seized two M-16 rifles and several hundred rounds of ammunition from the two men, both of whom were Indonesians, he said.

Maj. Gen. Didi Widayadi told el-Shinta radio station that officers on Wednesday seized 4 boxes of TNT, 1,200 detonators and 22,000 rounds of ammunitions in Semarang.

He also said that 25 sacks of potassium chlorate, the chemical used in the Bali blasts, were also found, along with unspecified laboratory equipment and several shoulder launched rockets.

"This has the (explosive) potential above that of the Bali bombs" he said.

He said both men were suspected members of Jemaah Islamiyah, adding that they were "possibly" linked to the Bali blasts. The two have yet to be charged.

"These are important arrests that come as a result of the work of the Jakarta and Bali police," Padmanegara said.

Earlier police said they had arrested several key suspects but were withholding details of the detentions because they feared news of them could make it more difficult to arrest additional suspects.

Police across Southeast Asia have arrested scores of Jemaah Islamiyah operatives over the last year, but several key figures are still believed to remain at large.

Most of the 34 people arrested over the Bali bombings are allegedly members of Jemaah Islamiyah, which wants to establish an Islamic state across Southeast Asia.