Police say more than 70 Indian police officers are missing following an ambush by Maoist rebels in central India.

Officials say Maoists attacked security forces in the southern jungles of Chhattisgarh state on Wednesday. A gunbattle ensued, and police say they have not been able to establish contact with the personnel involved in the fighting.

Communication was said to be difficult due to heavy rain.

Officials say reinforcements have been sent in to the site of the gunbattle.

In a separate attack in eastern India, police say Maoist rebels detonated a landmine, killing five people in the state of Jharkhand.

The victims were traveling in the Giridih district late Tuesday when the powerful explosion ripped through their vehicle.

The blast came at the end of a two-day strike called by the Maoists, who say they are fighting for land and jobs for the poor.

The rebels killed close to 75 police officers in Chhattisgarh in April and a month later bombed a bus in the same region, killing 35 people.

Prime Minister Manmohan Singh has called the Maoist insurgency India's most serious domestic security issue, with 20 of its 28 states affected.

The government has pledged to curb the insurgency in three years with a strategy that includes both police action and development.

Some information for this report was provided by AFP, AP and Reuters.