KANO, Nigeria (CNN) -

At least 30 people were killed Sunday in raids by suspected Boko Haram Islamists on four Christian villages in the northeastern Nigerian state of Borno, residents and a priest said.

Gunmen on motorcycles stormed the villages of Kwada, Ngurojina, Karagau and Kautikari, opening fire on residents and hurling explosives into homes and churches. The villages are near Chibok, scene of the April 14 abduction of more than 200 schoolgirls,

Barnabas Tanko, a member of a local vigilante group in Kwada, 10 kilometers (6 miles) from Chibok, said the gunmen, believed to be Boko Haram insurgents, attacked the village around 8:00 a.m.

Witnesses say the gunmen pursued fleeing residents into the bush and shot them dead.

In Kwada, the entire village, including its five churches, was burned by the marauding gunmen.

"We have confirmed that 30 bodies have so far been recovered in the four villages attacked by the gunmen," said Enoch Mark, a Christian priest in Chibok.

It is difficult to say how many people were killed because the gunmen on motorcycles pursued residents fleeing into the bush and shot them dead, Mark added.

"We now have to wait until things calm down to scour the bushes to collect bodies," Mark said.

Dark smoke coming from the directions of the four villages could be seen from Chibok. Mark said it was from burning homes.

"They are no doubt Boko Haram. They opened fire on residents, some worshipping in churches, and set buildings on fire with explosives," Tanko said.

"They burnt five churches and the entire village before proceeding to Ngurojina, Karagau and Kautikari," Tanko said.

Military response was slow, Mark said, allowing the gunmen ample time to inflict massive carnage on the villages.

A military fighter jet deployed five hours later and the gunmen sneaked into the bush, Tanko said.

Residents of the four villages who were able to escape have fled to nearby towns and Maiduguri, the state capital.