Worshippers who attended a mass religious event in Malaysia that is now linked to 840 coronavirus cases across Southeast Asia are cooperating with authorities, an organizer said, after the government said thousands of them were still being traced.

Muslim worshippers pray on the Al-Aqsa Mosque compound during the holy month of Ramadan in Jerusalem, on May 17, 2019. Photo: Xinhua

The four-day Islamic gathering held at a mosque near the Malaysian capital Kuala Lumpur is connected to 63 percent of all the 1,306 cases in the country - the highest number of infections in Southeast Asia, which has a total of more than 3,460 cases.

Malaysia has also recorded eight deaths.

The government said on Thursday that it had yet to trace 4,000 of the 14,500 Malaysian residents who attended. The health ministry said on Saturday it expected the number of cases to spike next week as it tried to track down unscreened participants of the February 27-March 1 religious event.

"After hearing reports of thousands or participants yet to be screened, many had returned to their district health departments or hospitals repeatedly until their names and details were recorded," Abdullah Cheong, a leader of the event's organizing team, said in a statement on Saturday.

"We are prepared and have given our full commitment to help the authorities deal with the pandemic."

He also said 12,500 people attended the gathering, including foreigners and 200 Rohingya refugees.

"Most of the new cases were found in Bangkok and were among young people who continue to have social activities, which can lead to more infections," Taweesin Wisanuyothin, a Public Health Ministry spokesman, told a media conference. 

The government has deployed the army on Sunday to help the police enforcement.