Here are the top 10 developments on this story:
India and Pakistan on Friday joined the resource-rich grouping that has Kazakhstan, Kyrgyzstan, Russia, China, Tajikistan and Uzbekistan as members.
The SCO collaborates on trade, economy, connectivity, energy, transport, banking and security. With the SCO's expansion to include India and Pakistan, PM Modi said the SCO would represent 42 per cent of humanity and nearly 22 per cent of global GDP.
PM Modi's brief speech at the summit also emphasised on the need for the member countries to fight all aspects of terrorism that he called one of the chief violators of human rights and values. He expressed confidence that SCO would give a hard push to fight terrorism.
With Prime Minister Nawaz Sharif listening in, PM Modi said unless all member countries make coordinated and bold efforts to fight terrorism - right from radicalisation to recruitment of terrorists, their training and terror financing - it would be "impossible" to resolve the problem.
India had halted dialogue with Pakistan, insisting that terror and talks could not go together. PM Modi had spoken to PM Nawaz Sharif for the first time in over a year when they met at a cultural gala organised in Astana ahead for the summit. But sources said it was only small talk.
At the meeting between President Xi and PM Modi, the two leaders are believed to have discussed multiple issues including those on which divergence between the two countries had amplified in recent months. One of them was a stretch of Beijing's "Silk Road" initiative to expand trade links between China and Eurasia that runs through PoK.
Quoting a Chinese foreign ministry statement, a Reuters report said President Xi emphasised on the two countries working to "appropriately" manage their differences. He also called for increasing trade and investment cooperation to let the two countries enjoy more "early stage profits" from large scale projects in infrastructure and industry.
Foreign Secretary S Jaishankar said "there was an understanding that where we have differences, it is important that differences should not become dispute".
India had been a long-time observer of the SCO, which was formed in 1996. Initially, the members were Kazakhstan, Kyrgyzstan, Russia, China and Tajikistan. Uzbekistan was inducted in 2001.
On the margins of the summit, PM Modi also had meetings with Kazakhstan President Nursultan Nazarbayev, Uzbekistan President Shavkat Mirziyoyey and Afghanistan President Ashraf Ghani. Later in the evening, PM Modi left for India.