The Pakistan interior ministry has reportedly issued a letter to the Home department warning that India has sent 400 Muslim men to Afghanistan for receiving training to be able to carry out attacks on the China-Pakistan Economic Corridor (CEPC) installations.

Pakistan's national newspaper Dawn said the ministry has issued directives for making "foolproof security arrange" in the Gilgit-Baltistan area.

The letter claimed that India is targeting installations "including bridges at Karakoram Highway" on the CPEC route, Dawn said.

The Gilgit-Baltistan government has reportedly beefed up security following the letter with top Pakistani security officials visiting the area.

Several bridges along the Karakoram Highway has been declared as "sensitive", Dawn added with random checks being carried out by authorities to spot any suspicious activities.

The authorities are also prepared to detain "suspicious" people, the Pakistan daily reported, adding that "preventative measures" were put in place in view of the "law and order" situation prevailing in the country.

The CEPC project is a high-profile engagement between China and Pakistan which involves the reconstruction of the Dera Ismail Khan-Zhob road, the Khuzdar-Basima and the 136-km Karakoram Highway.

However, the project between the two countries has not been going according to plan after Pakistan turned down China's offer of assistance on the Diamer-Bhasha dam in December after Beijing placed strict conditions including ownership of the project. 

Later, China "temporarily" stopped funding of some projects under the CPEC project after reports of growing "corruption" allegations.

The move "stunned" the Pakistan authorities who are hoping for billions of dollars pouring into the project which would help create jobs, improve infrastructure and boost trade.

China and Pakistan have signed six pacts to boost cooperation on the $50 billion CPEC, including one on building an airport at the strategic Gwadar port city.

The CEPC project is a high-profile engagement between China and Pakistan which involves the reconstruction of the Dera Ismail Khan-Zhob road, the Khuzdar-Basima and the 136-km Karakoram Highway.