Satpol PP officers show off their haul of Valentine's Day-themed trinkets last year. (Antara Photo/Suryanto)

Jakarta. Dozens of Indonesian couples suspected of doing "the nasty thing" have been detained in Valentine's Day raids in several major Indonesian cities.

Uptight authorities, concerned about residents' morality, staged raids in Surabaya, Pontianak and Malang on Saturday, barging in on lovers during hotel room trysts.

In Surabaya, where Mayor Tri Rismaharini has declared war on Valentine's Day, police and members of the public order agency, or Satpol PP, swooped on 22 hotels and detained 189 unmarried lovers by 7 p.m.

“The mayor instructed [residents] not to use Valentine’s Day to do the nasty thing," Irvan Widyanto, chief of Surabaya Satpol PP, told Detik.com. “We will send the detainees to Social Center in Keputih.

"They can go home on Monday if their family come to get them.”

In Pontianak in West Kalimantan, Satpol PP officers were also busy targeting unmarried lovers.

“We captured around 15 couples doing immoral acts, so it was around 30 people," Pontianak Satpol PP Chief Haryadi S. Tribowo told Tribunnews.com on Sunday.

"We also detained 14 underaged kids and 4 people without identity card. In total, we got around 50 people.”

Fifteen couples were also detained in Malang, East Java, local news portal Beritajatim.com reported.

“We raided guest houses in Lawang and Kepanjen district,” said Adj. Comr. Ainun Djariah, from Malang Police. “Some were students and didn’t even have ID cards.”

Young, unmarried couples in particular run the risk of detention every Feb. 14 when authorities crack down on romantic rendezvous.

The Indonesian Council of Ulema, or MUI, which is Indonesia's highest Islamic authority, tells young people every year that celebrating the event can lead to promiscuity and other acts that are not in line with their interpretation of religious teachings.