A total of 32 espionage modules backed by the Inter Services Intelligence have been neutralised in the country in the last three years and 50 people, including 40 Indians, have been arrested in this regard, the Lok Sabha was informed on Monday.

In a written reply to the House, Defence Minister A K Antony also said the Border Security Force has reported Chinese commercial and military activities in Pakistan's Sindh province, close to the India-Pakistan border.

"A total of 32 ISI-backed espionage modules have been neutralised in the country during 2010-13, resulting in the arrest of 50 espionage agents -- 40 Indians and 10 foreign nationals," he said.

On steps taken by the government to tackle the problem, he said a well-coordinated and multi-pronged approach is in place to tackle espionage activities by Indian and foreign nationals, including Pakistanis.

The efforts includes preventing infiltration and illegal cross border activities, gearing up intelligence machinery, coordination between different agencies of government, modernisation, strengthening and upgrading of state police and security forces, Antony said.

In reply to a question on Chinese involvement in spying at Gwadar port and Sindh in Pakistan, he said, "As per a BSF report, there is no Intelligence input pertaining to Chinese activities at Gwadar Port.

"However, some Chinese Commercial as well as military activities have been reported in Sind province. Chinese commercial activities are reported close to Indo-Pak border at many places," he said.