The Jakarta Composite Index fell more than three percent in late afternoon trade on Tuesday amid renewed global security concerns following bombings in Madrid last week that killed 200 people and wounded 1,500.
The index shed 3.3 percent to 700.18 in late afternoon trade, its lowest point since January 2. By 0815 GMT the index recovered partly and was down 2.68 percent.
Losers outnumbered gainers 114 to 10 while 48 shares were flat.
The index had dropped almost seven percent in the previous six trading days, despite a relatively peaceful parliamentary election campaign in Indonesia so far.
"There is nothing bad from the fundamental front, but sentiment was hit by weakness in global markets following Madrid's bombings," said Yudhistia Susanto, a fund manager at Batavia Prosperindo Aset Manajemen.
A huge car bomb ripped through the five-star JW Marriott Hotel Jakarta in August last year, killing 12 people and wounding 150.