The teenagers, aged 17 and 18, are accused of being involved in forcing a man into a car before allegedly kidnapping another man from a shop.

Emergency services were called to a unit in Lidcombe following reports a 36-year-old man had been assaulted and forced into a car just before midnight on November 4.

He was found suffering facial injuries at Bonnet Bay, in southern Sydney, about 11pm the following day and taken to Sutherland Hospital in a stable condition.

Police said the incident was linked to the kidnapping of a 44-year-old man from a shop in Regents Park on October 6.

The man was returned home the following day suffering minor facial injuries.

Last month, detectives charged three people over the incidents and they remain before the courts.

Following further inquiries, detectives searched a property at Yagoona and arrested an 18-year-old man about 6.25am on Wednesday. A 17-year-old boy was arrested shortly after at Condell Park.

Both have been charged with four offences including detaining a person in company with intent to ransom and assault occasioning actual bodily harm.

The 18-year-old was refused bail and appeared before Bankstown Local Court on Wednesday.

The boy was refused bail to appear before a children's court on Thursday.

Australian Associated Press