Lima, Peru (CNN) -- Peruvian authorities have deployed 1,500 troops and police to search for dozens of gas workers taken hostage by rebels in southern Peru this week.
A police captain was killed and two people were injured during the search operation Thursday, when suspected Shining Path rebels opened fire on a military helicopter, Peru's government ombudsman said in a statement.
The Maoist rebels have demanded $10 million in ransom for the hostages, the ombudsman said, in addition to explosives and weapons.
But government officials have said they will not negotiate with terrorists, and that searching for the kidnapped workers was a top priority, the state-run Andina news agency reported.
"We strongly reject any force or action that threatens the lives or health of the workers held hostage by terrorist criminals, and we demand the quick release of these people without any conditions," government ombudsman Eduardo Vega said in a statement.
Masked attackers kidnapped about 40 workers in the town of Kepashiato early Monday morning, Andina said.
Some of the hostages were employees of the international construction company Skanska, according to Andina. A company spokesman could not be immediately reached for comment.
The kidnapping comes after authorities' recent announcements that they had significantly dismantled and defeated the rebel group.
At its peak, the Shining Path spread terror in the country through a bombing campaign that targeted buildings and infrastructure such as electricity towers. Throughout the 1980s and 1990s, the government fought a campaign that greatly reduced the capacity of the terrorist group.
After Peruvian authorities captured a longtime leader of the group in February, President Ollanta Humala said the group was "no longer a threat to the country."
"These are armed remnants with a limited capacity to cause harm. ... Today this leader and all of the main leaders have been captured," he told TVPeru at the time.
Journalist Maria Elena Bellaunde contributed to this report.