Beijing hopes Taiwan will deal appropriately with the case of missing mainland tourists in the island and take action to crack down on organized human smuggling.
The mainland blamed Taiwan's tourism policy towards mainlanders for the disappearance, said Xue Guifeng, a senior official from the China National Tourism Administration Thursday in Beijing.
Taiwan media reported that the 17 mainland tourists arrived in Taiwan from Fujian Province after having passed through Thailand.
The group failed to report to the travel agency responsible for meeting the group on July 13.
Taiwan media reported the group was made up of 13 men and four women, all of whom are middle-aged.
Taiwan allows only mainlanders living, studying, working or travelling overseas to visit the island in tour groups.
"The practice has provided opportunities for snakehead groups to undertake illegal activities across the Taiwan Straits," said Xue.
"We are greatly concerned about the July 13 case because it involves the security and practical interests of 17 mainland people," he added.
He urged Taiwan authorities to take measures to crack down on snakeheads who organize human smuggling operations, lift various barriers restricting mainlanders from touring Taiwan and prevent similar cases from happening again.
The Beijing-based Taiwan Affairs Office earlier urged Taipei to open the island to mainland tourists.
Beijing opened the mainland to Taiwan tourists as early as 1987.
Taiwan travellers paid more than 3.66 million visits to the mainland in 2002 and 2.73 million last year, according to official statistics.
In contrast, less than 30,000 people from the mainland visited Taiwan last year because of Taipei's restrictions.