COLOMBO, SRI LANKA, OCT. 8 -- Indian peace-keeping troops arrested 50 Tamil rebels today in a crackdown to restore Sri Lanka's cease-fire after guerrillas massacred nearly 180 people.

Government spokesman Anura Gunasekera said Indian forces bolstered patrols in the island's north and east to counter a wave of violence by the Liberation Tigers of Tamil Eelam, the most powerful rebel group.

Officials said at least 176 persons had been killed since the violence began on Tuesday.

State-run All-India Radio, monitored in New Delhi, said 40 Tamil Tiger guerrillas were arrested in their northern stronghold of Jaffna and 10 in the eastern district of Batticaloa. The radio said some of the group's leaders were among those arrested but gave no details.

The Press Trust of India said the organization's top leader, Velupillai Prabhakaran, was among those arrested and was being interrogated by peace-keeping forces, although there was no official confirmation of the report.

The Tamil Tigers angrily repudiated the cease-fire after the suicide of at least 11 from the group in government custody on Monday.

"There's a shoot-on-sight order given to {Indian} forces to shoot any unruly elements and apprehend miscreants," Gunasekera, state television director general, told a news conference.

An Indian diplomat said Indian troops would shoot anyone caught with a weapon. At least 11,000 Indian soldiers and paramilitary police are in Sri Lanka.

India and Sri Lanka signed a peace accord on July 29 to end four years of fighting between Tamil separatists and the Sinhalese-dominated government.