STOCKTON, California — Police say the parents of missing twin infants in California are being uncooperative, and the couple is jailed as the search continues, reports CBS Sacramento.

Aaron Weddles and Princess Canez-Walker were arrested in Stockton on suspicion of child endangerment and child neglect Tuesday. Police had been searching for the family since they were alerted Jan. 4 that two adults and their children were missing, transient and possibly living out of a car, according to Stockton Police.

Police found the couple living in their car with a 4-year-old girl and 2-year-old twin girls, who were taken into the custody of child welfare officials. But another set of twins, a boy and girl who are 20 months old, weren't with them.

The pair faced a judge Thursday on unrelated charges of vandalism for Canez-Walker and drugs for Weddles. But Stockton police say they won't give them any information about the location of the missing twins, Ren and Setina.

Police say there's a possibility the twins are with family or friends, but also say there's a possibility of foul play because they don't know their location.

"The parents are not cooperating, they are giving conflicting statements, and if they would cooperate with us, we'd be able to find out where these children are at and that is the goal to make sure that they are safe," Stockton Police spokesman Joe Silva told CBS Sacramento.

{"author_name":"Stockton Police Department","author_url":"","provider_url":"","provider_name":"Facebook","success":true,"height":null,"html":"

SPD NEWS: MISSING 20 MONTH OLD TWINS UPDATE #HelpUsLocate #StocktonCrimeStoppersThe vehicle in the photographs, a...

Posted by Stockton Police Department on Thursday, January 11, 2018

Silva told the Stockton Record that when investigators met with Weddles on Jan. 9, Weddles told them, "You are the ones getting paid. Do your job."

No photos of the missing twins were available. Police described them as mixed ethnicity, Cambodian and African-American. They are appealing to the community for information about the location of the children.

© 2018 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.

Follow WFMY News 2 on Facebook and Twitter

► Make it easy to keep up to date with more stories like this. Download the WFMY News 2 App now