The number of foreigners coming to China has increased significantly in the first quarter of this year as a result of the continued improvement in the country's policies to facilitate cross-border travel, the National Immigration Administration said on Tuesday.

As China's visa-free transit policy was optimized in December, ports across the country recorded over 9.2 million entries made by foreign visitors between January and March, a 40.2 percent year-on-year increase, said Lin Yongsheng, spokesman for the administration, adding that 71.3 percent of these were visa-free entries.

On Dec 17, China optimized its visa-free transit policy by increasing the duration of visa-free transit to 240 hours for citizens of 54 countries, a significant increase from the previous 72 hours and 144 hours.

Under the optimized policy, eligible visitors can enter China through 60 ports visa-free, and stay in or travel across 24 provincial-level regions.

Lin said the policy allows foreign travelers to stay in China for a longer period of time and explore more places. Nearly 60 percent of foreigners entering China choose to cover different regions during their stay, which in turn is boosting inbound tourism, he added.

Since the policy was optimized, the number of foreign visits to popular Chinese cities, such as Huangshan in Anhui province, Wuyishan in Fujian province and Zhangjiajie in Hunan province, has increased 21.6 percent year-on-year, according to the spokesman.

The administration plans to further enhance institutional openness in immigration management, which will involve the introduction of more efficient entry, exit and residency policies, the implementation of new measures to streamline customs clearance for travelers, and the facilitation of smoother and more convenient exchanges between Chinese citizens and foreigners, he said.

In the first quarter of the year, immigration management agencies across China recorded 163 million entries and exits, a 15.3 percent year-on-year increase, Lin said, noting that about 17.4 million of these trips were made by foreigners, up 33.4 percent year-on-year.

At the same time, China's immigration authorities have continued to crack down on criminal activities that interfere with border management, conducting investigations in 2,851 such cases and detaining 8,402 suspects in the first quarter, he said.

The authorities have also cracked 128 illicit drug cases, and seized 201 guns and more than 5,400 bullets, he added.