Hong Kong police on Tuesday arrested a 24-year-old Pakistani suspect in connection with the killings of four prostitutes over the past few days in the city.

The man, who was identified by the police as a Hong Kong resident of Pakistani descent, was arrested at a ferry terminal in the early hours with the help of police in neighboring Macao, about 40 kilometers west of Hong Kong.

"In the suspect's possession, we recovered two mobile phones which belonged to two of the murdered victims," Steve Li, a senior police superintendent, told local television channel, without giving the name of the suspect.

Li said the suspect was being detained for further inquiries and the police will be issuing criminal charges at some point later.

Li said it appeared that robbery was the motive behind the murders of the four women.

"We do not want to guess, but based on the information so far we gathered, and also the ransacking and the looting of the victims' properties, we believe there's one possibility of robbery, " he said.

Four sex workers have been killed in Hong Kong since Saturday and three of the women were believed to have been strangled. All four had been operating out of their own flats.

As one of the world's safest major cities, Hong Kong rarely reported murders and other violent crimes.

Under Hong Kong law, prostitution is legal if carried out by one woman operating alone in a single location, the so-called "one- woman brothel." Soliciting for sex is illegal, however.