AFP/ Islamabad

Chinese President Xi Jinping on Tuesday hailed a $46 billion economic corridor as a "historic development opportunity" for Pakistan, but security fears linger over the project which involves major construction in highly unstable areas.

Pakistani and Chinese officials on Monday signed more than 50 accords to inaugurate the China-Pakistan Economic Corridor, which will create a network of roads, railways and pipelines linking China's restive west to the Arabian Sea through Pakistan.

The project is part of Beijing's "Belt and Road" plan to expand its trade and transport footprint across Central and South Asia. It will give China easier access to Middle Eastern oil via the deepwater port of Gwadar in southwest Pakistan.

The Chinese plan also aims to boost Pakistan's underperforming economy, which the IMF projects will grow 4.3 percent this year, and tackle its energy crisis.

Beijing and Islamabad have long enjoyed close ties and Xi's speech to Pakistan's parliament Tuesday was full of the flowery rhetoric that typifies their official exchanges.

"Today Pakistan has a historic development opportunity. Prime Minister Sharif has crafted the vision of the Asian tiger dream," he told lawmakers before flying on to Indonesia for a summit.

- Rebel strife -

But away from the handshakes and backslapping, there are real security concerns over much of the plan, which relies on developing Gwadar -- control of which was passed to a Chinese company in 2013.

The port lies east of the Strait of Hormuz, through which much of the Middle East's crude production passes.

But linking Gwadar to the rest of Pakistan and on to the western Chinese city of Kashgar, 3,000 kilometres (1,860 miles) away, would involve major infrastructure work in Baluchistan.

This is one of Pakistan's most unstable provinces and has been dogged for over a decade by a bloody separatist insurgency.

Ethnic Baluch rebels, who oppose Gwadar's development while the province is not independent, have in the past blown up numerous gas pipelines and trains and attacked Chinese engineers.

Earlier this month the Baluchistan Liberation Front claimed an attack in the province that left 20 construction workers from elsewhere in Pakistan dead, the bloodiest separatist incident since 2006.

Siddiq Baloch, editor of the Balochistan Express newspaper, said the rebels want to scare off investors and developers who are working with the Pakistani government -- such as the Chinese.

"There is the thinking that by doing this, they want to disrupt the working of the economy, disrupt the administration, challenge the administration in the area," he told AFP.

Suppressing the rebellion by force in Baluchistan's desolate and sparsely-populated landscape, much of which is desert and mountains, has proven difficult.

Abdul Malik Baloch, the Baluchistan chief minister, said strenuous efforts were under way to negotiate with the rebels.

"This is my honest opinion, this is the only way -- to start talking and bring the insurgents to the table," he told AFP.

In a bid to allay fears, Xi's Pakistani counterpart Mamnoon Hussain told him a special army division would be given responsibility for the safety of Chinese workers, a presidential source told AFP.

- Managing risks -

Baluch rebels on Monday attacked an airport in Gwadar district, causing damage but no casualties, in a vivid reminder of the dangers.

Andrew Small, author of "The China-Pakistan Axis", said China's recent experience of working in Pakistan had given it a good idea of which projects could proceed in spite of security worries.

"China is certainly not completely confident that all the projects will be protected, but they think these security problems are one of the main reasons that it's so important that they move ahead, for the sake of Pakistan's stability," he told AFP.

Even if not all the projects envisaged in the corridor plan went ahead, Small said, "the scale is so large that it should still have a major economic impact regardless".

And while the Chinese projects dwarf an American assistance package to Pakistan of $5 billion that began in 2010, Small said Beijing was not interested in supplanting Washington in the region, preferring to see the US maintain its support.