Lenovo has announced a voluntary recall of four models of its ThinkPad X1 Carbon 5th Generation notebooks.

An unfastened screw in the products can damage the batteries, causing overheating and posing a fire hazard, the firm said yesterday.

The four affected models are 20HQ, 20HR, 20K3 and 20K4. All were manufactured between December 2016 and October 2017.

They were sold in direct sales or online sales, or through the brand's business partners during the same time period.

Affected customers will receive free service inspections, said Lenovo. It advised customers to turn off their notebooks and refrain from using them until the servicing is done.

"Lenovo highly values our customers and regrets any inconvenience this recall may cause," it said.

The firm has received three customer reports worldwide of an overheating condition related to an unfastened screw, which resulted in damage to the customer's laptop. It has not received any reports of damage to other property or persons.

Customers can check the support telephone list at https://pcsupport.lenovo.com/sg/en/supportphonelist

They can also confirm if their products are affected at https://pcsupport.lenovo.com/sg/en/supportphonelist.

Those with further queries can call Lenovo Services on 800-852-6201 or an authorised warranty services provider.