Gambling and gaming websites in Hong Kong were hit in April by several distributed denial of service (DDoS) attacks, which intended to take the sites offline and mulct money from the operators, according to a U.S-based cyber security firm.

The International Business Times reported that the Security Engineering and Response Team at Arbor Networks detected a sudden but unusual spike of traffic in at least 29 online gambling and gaming sites during the first two weeks of April.

Kirk Soluk, the manager of the company’s Threat Intelligence and Response team, monitored 28 and 39 percent of all attacks greater than 10 Gbps in size hit Hong Kong. Soluk said the attack started on April 6.

What made the attack unusual, according to Soluk, was the fact that Hong Kong had overtaken the U.S. in terms of targeted DDoS attacks during the first two weeks of April. He said US has always been a top destination for targeted attacks.