Police arrested a 22-year-old Filipino woman for carrying a stun gun at Hong Kong International Airport on Tuesday. At 8:30pm, when the woman was at the security-check area preparing for departure, a security guard found the 11.5-centimeter gun in her carry-on luggage, Sing Tao Daily reported.

The guard reported the incident to police. After an initial investigation, police arrested the woman for alleged possession of arms without a license.

According to figures supplied by the airport unit of the Hong Kong Police Force, 150 people were arrested for possession of stun guns or tear spray in the first half of this year, compared with 186 arrests in the same period of 2016, Apple Daily reported.

Last year, a 22-year-old male Filipino tourist was convicted of possession of arms without a license and was fined HK$500 (US$64) in Tuen Mun Magistrates’ Court, Headline Daily reported.

The man said he had bought the stun gun in Manila for self-defense before traveling to Hong Kong.