Schoolchildren abducted from a Nigerian Catholic school last month and released over the weekend reunited with their parents overnight into Wednesday.

Details surrounding their release were not made public, and the government has not said if any ransom—common in such abductions— was paid.

At least 303 schoolchildren were seized in Niger State together with 12 of their teachers when gunmen attacked St. Mary’s Catholic School in the Papiri community on November 21.

Fifty escaped in the hours that followed, and at least 150 are still held, together with the teachers.

The freed schoolchildren arrived in Papiri in several buses accompanied by military trucks. They were then received by the school principal, being handed over to their anxiously waiting parents.

One parent, Luka Illaya, expressed his relief over the release of one of his children but said another still remained captive.

Most of the freed children—between the ages of 10 and 17, according to the school—arrived wearing soccer jerseys, robes, and slippers.

Officials said they had been in Nigeria's capital, Abuja, since the news of their release broke on Sunday night.

No group has claimed responsibility for the abduction, but locals blamed armed gangs that target schools and travelers in kidnappings for ransoms across Nigeria’s conflict-battered north.

The Niger state attack was among a spate of recent mass abductions in Nigeria and happened four days after 25 schoolchildren were seized in similar circumstances in neighboring Kebbi state’s Maga town.

A church in the southern Kwara state was also attacked around the same time—the 38 worshipers abducted in that attack last month have also been freed.

Under pressure at home and from U.S. President Donald Trump—who has alleged that Christians are being targeted in Nigeria’s security crisis—Nigeria's President Bola Tinubu has promised he will not relent until all hostages are freed.

Nigerian authorities usually do not say much about rescue efforts, and arrests in such cases are rare.

Analysts believe that's because ransoms are usually paid. Officials do not admit payment of ransoms.