A Swedish court said Friday it has remanded 13 men in custody on suspicion of preparing aggravated assault, possibly targeting an asylum reception centre.
The 13 were arrested late Monday near an asylum centre in Nynashamn, south of the Swedish capital of Stockholm.
Another 17-year-old man was released by the Sodertorn District Court.
Acting on a tip, police said they found iron bars, knives and axes when they searched cars used by the 14 men.
They were not identified, but the Expo magazine that tracks racist and right-wing extremist groups said several were Polish nationals.
The request to remand the men in custody was to prevent them from leaving the country or hindering the probe, for instance by comparing their statements, prosecutor Patrik Viklund said on Swedish television.
Three of the suspects were reportedly also involved in another incident at the end of January when they were arrested on suspicion of assault following an anti-immigrant protest rally in Stockholm.
The Swedish Migration Agency said it has stepped up security at its reception centres in the Stockholm region.
Sweden in 2015 registered a record 163,000 asylum bids. Last year, the country also registered a rise in suspected arson attacks at reception centres for new arrivals.