BEIJING -  Ships carrying personnel for China's first overseas military base, in Djibouti in the Horn of Africa, have set sail to begin setting up the facility, as China's rapidly modernising military extends its global reach.

Djibouti's position on the northwestern edge of the Indian Ocean has fuelled worry in India that it would become another of China's "string of pearls" of military alliances and assets ringing India, including Bangladesh, Myanmar and Sri Lanka.

China began construction of a logistics base in Djibouti last year. It will be used to resupply navy ships taking part in peacekeeping and humanitarian missions off the coasts of Yemen and Somalia, in particular.

It will be China's first overseas naval base, though Beijing officially describes it as a logistics facility.

State news agency Xinhua said late on Tuesday the ships had departed from Zhanjiang in southern China "to set up a support base in Djibouti".

Navy commander Shen Jinlong "read an order on constructing the base in Djibouti", but the news agency did not say when the base would begin operations.

Xinhua said the establishment of the base was a decision made by the two countries after "friendly negotiations, and accords with the common interest of the people from both sides". "The base will ensure China's performance of missions, such as escorting, peace-keeping and humanitarian aid in Africa and west Asia," it said.

"The base will also be conducive to overseas tasks including military cooperation, joint exercises, evacuating and protecting overseas Chinese and emergency rescue, as well as jointly maintaining security of international strategic seaways," Xinhua said.

Foreign ministry spokesman Geng Shuang told a daily news briefing the base would enable China to make "new and greater contributions" to peace in Africa and the world and would benefit Djibouti's economic development.

Djibouti, which is about the size of Wales, is at the southern entrance to the Red Sea on the route to the Suez Canal. The tiny, barren nation sandwiched between Ethiopia, Eritrea and Somalia also hosts US, Japanese and French bases.

The People's Liberation Army Daily said in a front-page commentary the facility was a landmark that would increase China's ability to ensure global peace, especially because it had so many UN peacekeepers in Africa and was so involved in anti-piracy patrols.

China would not seek military expansionism or get into arms races no matter what happened, the newspaper said. "These promises will not change because of the construction of the overseas logistics base," it said.

The state-run Global Times said in an editorial there could be no mistake that this was in fact a military base. "Certainly this is the People's Liberation Army's first overseas base and we will base troops there. It's not a commercial resupply point. It makes sense there is attention on this from foreign public opinion," said the paper, which is published by the official People's Daily.

China's military development was about protecting its own security, it said. "It's not about seeking to control the world." There has been persistent speculation in diplomatic circles that China would build other such bases, in Pakistan for example, but the government has dismissed this.

According to CNN, China has expanded its military ties across Africa in recent years. According to a report by the European Council on Foreign Relations (ECFR), cooperation with Africa on peace and security is now an "explicit part of Beijing's foreign policy."

In 2015 Chinese President Xi Jinping committed 8,000 troops to the UN peacekeeping standby force — one fifth of the 40,000 total troops committed by 50 nations — China also pledged $100 million to the African Union standby force and $1 billion to establish the UN Peace and Development Trust Fund.

More than 2,500 Chinese combat-ready soldiers and police officers are now deployed in blue-helmet missions across the African continent, with the largest deployments in South Sudan (1,051), Liberia (666), and Mali (402), according to the ECFR.

"Blue-helmet deployments give the PLA a chance to build up field experience abroad - and to help secure Chinese economic interests in places such as South Sudan," said the ECFR report.

Africa is home to an estimated one million Chinese nationals, with many employed in infrastructure projects backed by the Chinese government.

"China's involvement in African security is a product of a wider transformation of China's national defence policy. It is taking on a global outlook ... and incorporating new concepts such as the protection of overseas interests and open seas protection," said the ECFR report.

China joins the US, France and Japan, among others, with permanent bases in Djibouti, a former French colony with a population of less than one million residents.

Though small in both population and size, Djibouti's position on the tip of the Horn of Africa offers strategic access to the Bab el-Mandeb Strait.

The strait, which is only 18 miles wide at its narrowest point, connects the Mediterranean Sea via the Suez Canal and the Red Sea to the Gulf of Aden and the Indian Ocean beyond.

One of the world's most important sea lanes, millions of barrels of oil and petroleum products pass through the strait daily, according to GlobalSecurity.org.

US Marine Corps Gen Thomas Waldhauser, the head of the Pentagon's Africa Command, stressed Djibouti's location during a visit to the US Camp Lemonnier garrison there earlier this year.

"This particular piece of geography is very, very important to our strategic interests," Waldhauser said in joint appearance with US Defence Secretary James Mattis. The US military has some 4,000 troops at Camp Lemonnier, a 100-acre base for which it signed a 10-year, $630 million lease in 2014, according to media reports.

Elsewhere in Djibouti, the US military operates the Chabelley Airfield, from which the Pentagon stages drone airstrikes, likely into Somalia and across the Bab el-Mandeb Strait into Yemen, according to the Center for the Study of the Drone at Bard College in New York. The Pentagon is investing millions in the base, and satellite photos show several construction projects, the center reported last year.