Importing Nominatim database error: libgeos can’t be opened

Hello everyone.

I don't have much to say about. I executed setup.php, the import started running, and then this happened:

/root/Nominatim/osm2pgsql/osm2pgsql: error while loading shared libraries: libgeos-3.3.3.so: cannot open shared object file: No such file or directory
ERROR: Error executing external command: /root/Nominatim/osm2pgsql/osm2pgsql -lsc -O gazetteer --hstore -C 486 -P 5432 -d nominatim /root/brazil-latest.osm.pbf
Error executing external command: /root/Nominatim/osm2pgsql/osm2pgsql -lsc -O gazetteer --hstore -C 486 -P 5432 -d nominatim /root/brazil-latest.osm.pbf

I'm lost at this one. I've ran in some errors already, regarding postgres and postgis versions, but I just can't understand this one.

I'm running this on a CentOS 6.2 machine. Postgis 1.5, PGSQL 9.1.