Mexico City, Nov 23 (IANS): Mexican authorities stopped a first attempt by members of the Central American migrant caravan to seek asylum in the US, whilst Washington continued to strengthen border security in the face of their mass arrival.

The authorities supported by federal and local police on Thursday blocked access to the El Chaparral checkpoint for some 200 of the more than 4,000 migrants who have arrived in recent days in the Mexican border city of Tijuana, reports Efe news.

The migrants marched to El Chaparral from the shelter they are occupying in Tijuana, as US authorities closed the San Ysidro border checkpoint for almost an hour for a security drill.

For nearly an hour, agents from the US Customs and Border Protection (CBP) deployed security measures as a test of the possibility of a potential massive arrival of migrants at this point of entry into their territory.

CBP did not indicate the reasons for this atypical plan and merely said in a statement: "CPB is continually assessing the capabilities of our facilities and have been making - and will continue to make - necessary preparations."

Staff from Grupo Beta, a service by the National Institute of Migration of Mexico, which assists migrants crossing through Mexico to the US, met with members of the caravan asking them to call off the march, as well as to make them aware of the possibility of obtaining work in Mexico.

A representative of the Beta Group told them that in Tijuana there is strong labour supply and that having a job can help them as they go through the asylum process with the US.

Additionally, Mexico's Ministry of Labour and Social Security confirmed that the Otay Mesa Industrial Association in Tijuana has 3,500 jobs available for migrants to regularise their immigration status.

He confirmed that there are 217 companies, Mexican and foreign, who offer workplaces in Tijuana and other cities in Mexico, to which migrants can move once they comply with the regularization protocols.